G'day Guys 
I thought a troubleshooting guide would be handy for the noobs or less technically minded members amongst us. The key to troubleshooting is efficiency: the quicker you can find and fix problems, the faster you can get back to work (or play). Its a given that at some time your computer will go belly-up. Its a cruel reality that computer owners have all learned to live with, and accept, beacuse thats just the way things are. The only way to approach troubleshooting your computer problems is through a systematic and methodical approach. Its a relativley simple process of elimination.
Modern computing has an ever-growing list of things that can go wrong. With clock speeds ramping up and sofware becoming more complex, there are literally thousands of errors that could detail your session in front of the screen. With that in mind, it's less important to know how to fix, say, obscure error 4137 than to have a solid troubleshooting procedure down pat.
Here is the method by which I troubleshoot my own personal machines, its recommended that you adopt something very similar.
Step 1. Playing dead
You've just sat down at the PC to get some work done, pressed the magic button on the front panel, and nothing happens. There's no LED letting you know that that the machine is in the throes of booting, and you can't hear any fan noise. Before panicking, there are a few simple checks to go through:
*verify that juice is getting through to the systems power supply unit (PSU) and that its set to the correct voltage, and
*sniff the air behind the PC. Power supplies quite commonly go south, and when they do, they give of a telltale aroma of burnt capacitors and circuit boards.
If a smell is coming from the PSU vent, you've probably overloaded it and it couldn't take the strain. Alternatively, it may have just died of natural causes/old age or an accumulation of dust and wear and tear. A new PSU isn't that expensive , but you need to purchase a reputable brand, for example: Antec; Tagan, Enermax; OCZ (a little overkill if you aren't oc'ing, there are cheaper available). PCnerd2357 has posted a cool little guide for choosing a replacement PSU here.
Make sure the new PSU you put in has an output in watts equal to the previous one. Most basic PC's can get away with a 300W unit; but if you are running multiple hard disks, a current generation processor and a modern graphics card, you are better off going for a 400W unit or higher. Pls try and choose a brand name PSU, instead of opting for a generic no-name brand. XMS has included a really handy PSU calculator here. After replacement, turn the PC on and it should boot without error. Should your PC's fans still refuse to spin, chances are that:
*it may be the PSU again;
*a small likelyhood it's the motherboard;
*your power button on the PC itself (I personally have encountered this, although rare on quality cases)' or
*you may have dislodged a connector accidentally.
#Some other handy guides, for suggested browsing:
FragTeks guide to jumpstarting a PSU- here.
FragTeks guide to testing your PSU rails- here
Tom's hardware have a really cool PSU stress test- here
If the power seems ok, you have to start going through a list of possible faults, working back to isolate the root cause.
Open Heart Surgery
Start by opening the PC's case. If you have recently replaced your power supply, examine the motherboard, paying special attention to the the cluster of tall silo-shaped capacitors arrayed around the motherboard's CPU socket. These are generally responsible for regulating the voltage and current to your slots and CPU socket. If you have blown the PSU and sent a power spike down the line, the capacitors will bulge at the top, indicating a fatal surge.
# Note: there is an interesting article here, relating to other causes of problems with capacitors. Problems mainly associated with P4 motherboards.
The only recourse is to pray that the spike hasn't made it beyond the motherboard to your HDD system or expansion cards. The components will have to be pulled out and tested individually. The best bet is to either test them in a friends computer, or take them to a reputable reseller and get them to test them for you. If thePSU powers up (with CPU and GPU fans) but nothing else happens, there could be a problem with the motherboard, CPU or RAM. If the PSU is fine but nothing happens when you boot-no light on the monitor and no warning beeps-its generally the motherboard that isn't functioning correctly. Just be sure to eliminate other possibilities before you throw it out.
Shuffling Chips and Cards
A faulty memory module will often halt a computer during the boot, so pull out the RAM sticks one-by-one and try to boot with different memory configurations. If that doesn't work, pull out all your expansion cards (save the video card) and turn the power on. If the machine boots, start replacing the cards one-by-one to isolate the faulty device. Sometime the peripheral component interconnect (PCI) cards can work loose from their motherboard connection, and pulling them out and replacing them is enough to enable the PC to boot.
# Note: just remember to start with a minimal setup and replace components, until you find the fault.
Working Loose
If there's obviously nothing wrong with the RAM or expansion cards, take a look at the connections inside the PC. Disconnect the drives and check the IDE cables for any obvious signs of damage or wear. Reconnect each one, trying to boot at each stage. If these tricks don't work, take a closer look at the motherboard and CPU. Pull them out and test them individually (if you have access to alternate, compatable hardware). If not, ask your local reseller to run motherboard and CPU tests. It shouldn't cost more than a few dollars.
Step 2. No signal to video card
When you turn the power on and your hard drives spin but your monitor remains in standby mode, there are only a few things that can be wrong:
*a cable has become dislodged at some stage, so check the connections between the video card and monitor (if possible try the monitor on another machine or use one that you know is operational);
*are there any error beeps when your machine powers up? If so check your video card. Pull it out of the AGP/pci-E slot, reseat it and try again. If possible try it with another card that you know works.
If the machine is silent when you first boot it (excluding fan noise), its almost certainly your motherboard is causing the problems.
Step 3. The Post
If the PC is powering up enough to emit a series of beeps, you've made it to the power on self test (POST). And at least the motherboard is functioning correctly, or at least ok enough to try to let you know what is wrong. When a machine is turned on, the first job of the basic input/output system (BIOS) is to perform the POST, a diagnostic program that checks the hardware. Technically speaking, this occurs before the boot procedure. The PC speaker is used to warn of the error because the POST executes before video is initialised. Look in your motherboard manual for how to interpret the series of warning tones, which vary from one manufacturer to another. For a generic rundown of POST tones for common BIOSes, go to http://www.pcguide.com/ts/x/sys/beep/index.htm . The POST tests many individual components including DRAM refresh, system timer, processor, keyboard controller, cache memory and video memory. In the case of boards with an AMIBIOS, continuous beeping indicates a problem with either the system memory or video controller. After checking the tone pattern with your motherboard manual and finding the cause of the fault, fixing it can often be just replacing a faulty RAM module or inserting a new video card.
Step 4. Putting the boot back in
Your PC can come up with myriad errors before being able to load Windows or any other form of OS. Here's a rundown on the most common problems that might prevent you from booting Windows, and how to fix them.
Safe Mode
msconfig utility to boot into safe mode
First, attempt booting Windows in 'safe mode', which loads a minimal set of drivers. Autoexec.bat and config.sys are not accessed and most of the Windows registry is ignored. Press F8 during the initial boot process to load the boot menu. Select 'safe mode' from the options list and hit Enter.
You can also opt for step-by-step confirmation to isolate an individual line that may be at fault in the autoexec.bat or config.sys files. If there's a problem with a setting in the registry or device drivers, choose the 'safe mode' option that loads the Windows graphical user interface. From here you can make the necessary changes to remove the source of the boot failure.
Missing Files
One of the most common error messages in Windows 2000 and XP machines is "NTLDR is missing. Press any key to restart". It signals a fault in one of three files: ntldr, ntdetect.com, or boot.ini. This fault is sometimes caused by an out-of-date BIOS, which can be corrected by a flash update.
#Note: Pls check with your motherboard manual or manufacturers website for how to flash your BIOS-but be careful. If done incorrectly, it can corrupt the BIOS and render your machine unbootable.
One way to get around the NTLDR error message (after checking your BIOS version) is to use a boot disk containing the appropriate files and replace them as necessary. The disk can be made as a precaution while your machine is still healthy, or belatedly on another machine. For details of how to make a boot disk under Windows to suit FAT and NTFS partitions, see the support article on the Microsoft website http://support.microsoft.com/default.aspx?scid=kb;EN-US;301680 . The preferred method is to let the original install cd for Windows 2000 or XP do the hard work. Boot your PC with this cd in the drive and hit R to enter the Repair Options page. Press R again, and when the prompt appears for selecting a repair option, press M. Now hit the up arrow a couple of times to select Verify Windows system files, and Enter to proceed.
After you have made the selection, move down to Continue and press Enter. You'll be prompted to insert an emergency repair disk. If you don't have one, press L to receive a message telling you where Windows is located on your HDD. All you have to do is press Enter and Windows will automatically make the repairs. On completion, you should be able to reboot the machine to Windows as normal.
XP's Fatal Stop Error
When installing a new piece of hardware under Windows XP, there is always a chance that the OS won't boot. You will receive a fatal stop error and one of those ominous blue screens just before launching the graphical environment. This is actually part of Windows XP's hardware tracking. When calling MS and activating XP, a list of the hardware in your machine is drawn up. This is cross-referenced at boot-up with the saved configuration. If a number of changes are detected, a fatal error is indicated. It isn't a given that you'll have to reactivate Windows. It depends on how much has changed. Upgrading your CD-ROM is unlikely to cause a boot to fail, but changing the motherboard is almost guaranteed to do it. This is because of the motherboard's individual components maintain separate entries in the Device Manager
MBR Misinformation
Being confronted with the message "Missing operating system" or "Non-system disk error" was relatively common under DOS and Windows 95, but they are rarely found in the newer versions of the OS. They mainly display if the MBR (Master Boot Record) doesn't contain the correct boot information or if there is no active partition on the drive. The boot sector is therefore invalid and needs rewriting. Below there are instructions for "fixmbr and fixboot", when using the recovery console to rewrite a boot sector.
Windows Recovery Console
For hardcore troubleshooters, the Windows Recovery Console is one of the most useful inclusions in Windows 2000 and XP. It grants limited access to FAT, FAT32 and NTFS volumeswithout booting to a full blown Windows environment. It's often used to perform disk maintenance or make basic changes to system files, as the user is equipped with a powerful yet minimal set of tools.
#Note: Remember, you'll need Administrator rights on the broken machine before you can use the console. This is designed to protect the data caught on NTFS partitions. Its possible to make devastating system-wide changes through the misuse of the Recovery Console, so be wary. Should you be unsure if the OS uses a file, err on the side of caution. Don't fiddle...you have been warned!!!
Fixmbr and Fixboot
I'm gonna allow MS and their knowledge base support articles do the talking here.
fixmbr
fixboot
Disabling services
The Recovery Console can also turn on and off system services executed at startup. If a particular device or service is causing errors, try disabling it and restarting the computer. You can use the listsvc command to display all the services or drivers that can be disabled, while the enable and disable commands set the start_type values for each service. Each service or driver can be set to one of:
SERVICE DISABLED, SERVICE_BOOT_START, SERVICE_SYSTEM_START, SERVICE_AUTO_START or SERVICE_DEMAND_START. Typing disable <service-name> will turn a service off. Entering enable <service-name><start_type> at the console will set the start_type value to whatever you specify. After you have made all your changes, type exit at the prompt to lock your changes, and reboot your PC.
Recovery Console Commands
Windows 2000 recovery console commands
Windows XP recovery console commands
Step 5. Windows Boot Errors
After you have managed to get your PC booting into Windows, you're halfway home. But Windows itself can cough up all manner of errors during the boot process as its initialising drivers and accessing the registry. When you are troubleshooting an application, pay close attention to the error messages. Note down what you did to generate the fault, only with this information can you start to draw up a list of probable faults.
Device not responding
If you get a Device Not Responding error when you load Windows , the first thing to do is ensure you have the right driver installed:
*open the Control Panel and click on the system icon. Select the Hardware tab and click on the Device Manager button to launch the manager. Any devices with errors will display with either an exclamation or question mark beside their entry;
*double-click any malfunctioning device to open the properties window. In the general tab you will be able to read a description of what is wrong with the device. Usually the problem will be caused by either a missing driver or a hardware conflict. In the case of the former, select the Driver tab and click on the Driver Details button to gather information on the file and version of the driver in use;
*check the manufacturer's website for the appropriate driver with a higher version number than the one you are running and install it using the Update Driver button under the Driver tab.
External Devices
Troubleshooting an external device is a two part process. You have to check the individual driver for the external hardware and the chipset driver to ensure that Windows can actually communicate efficiently with it. With regards to USB 2.0 and Firewire, you'll need to ensure that you have the latest patches and Service Packs for your version of Windows. Windows XP introduced USB 2.0 support in SP1, while Windows NT requires SP3 to provide high-speed USB functionality. Firewire support was rolled into the boxed versions of Windows XP and 2000, but later SP must be installed before its stable and reliable.
The Registry
If you are getting all manner of startup errors pertaining to half installed software packages or missing DLL files, the key to fixing the problem requires a trip to the registry. The registry is a database that stores your Windows settings and options for installed software. Every Windows system setting for your PC resides in the registry, from applications installed to screensaver and desktop wallpaper settings.
Windows 9x-based machines have two registry files, named USER.DAT and SYSTEM.DAT, which are stored in the Windows folder. Windows 2000, XP and 2003 maintain separate registry files for each user.
Over a period of time the Windows registry becomes clogged, with all the programs you install adding their own little entries to it. Theoretically when you uninstall a program its registry entries are erased, but this often doesn't happen. Over the course of several years of installing and removing applications, the registry winds up full of redundant entries, which in turn impact on performance, or in a worst-case scenario, produce errors.
One way to go ahead and fix any unwanted entries is to use a dedicated registry-cleaning application like RegCleaner- http://www.worldstart.com/weekly-download/archives/reg-cleaner4.3.htm , but it can also be done manually.
#Note: bear in mind that playing with the registry and deleting keys can be potentially harmful to your machine, so be sure to backup the registry files before you begin.
There are six main branches, each containing a specific portion of the information stored in the Registry. They are as follows:
* HKEY_CLASSES_ROOT - This branch contains all of your file association types, OLE information and shortcut data.
* HKEY_CURRENT_USER - This branch links to the section of HKEY_USERS appropriate for the user currently logged onto the PC.
* HKEY_LOCAL_MACHINE - This branch contains computer specific information about the type of hardware, software, and other preferences on a given PC, this information is used for all users who log onto this computer.
* HKEY_USERS - This branch contains individual preferences for each user of the computer, each user is represented by a SID sub-key located under the main branch.
* HKEY_CURRENT_CONFIG - This branch links to the section of HKEY_LOCAL_MACHINE appropriate for the current hardware configuration.
* HKEY_DYN_DATA - This branch points to the part of HKEY_LOCAL_MACHINE, for use with the Plug-&-Play features of Windows, this section is dymanic and will change as devices are added and removed from the system.
Each registry value is stored as one of five different data types:
* REG_BINARY - This type stores the value as raw binary data. Most hardware component information is stored as binary data, and can be displayed in an editor in hexadecimal format.
* REG_DWORD - This type represents the data by a four byte number and is commonly used for boolean values, such as "0" is disabled and "1" is enabled. Additionally many parameters for device driver and services are this type, and can be displayed in REGEDT32 in binary, hexadecimal and decimal format, or in REGEDIT in hexadecimal and decimal format.
* REG_EXPAND_SZ - This type is an expandable data string that is string containing a variable to be replaced when called by an application. For example, for the following value, the string "%SystemRoot%" will replaced by the actual location of the directory containing the Windows NT system files. (This type is only available using an advanced registry editor such as REGEDT32)
* REG_MULTI_SZ - This type is a multiple string used to represent values that contain lists or multiple values, each entry is separated by a NULL character. (This type is only available using an advanced registry editor such as REGEDT32)
* REG_SZ - This type is a standard string, used to represent human readable text values.
Step 6. Stability Issues
If your machine is crashing randomly, you'll have to do a little more work. A possible cause is a faulty RAM chip. Try pulling out the RAM modules one at a time, booting the machine between each change, and keeping an eye on the machines performance. If this makes no difference, an overheating CPU could be causing the error. The most obvious sign that your CPU is cooking itself is a tendency for the PC to reboot at seemingly random moments. Generally it happens when the PC is under load because it warms up as more tasks are placed on the CPU. One of the trickiest things about troubleshooting a heating issue is that by the time the PC reboots, the processor has often cooled enough to enable it to start normally. The machine will be perfectly stable again until the CPU is stressed again. The best way to fix this is by:
*ensuring the HS is firmly attached to the CPU;
*re-apply thermal grease (Arctic Silver) after removing the old paste, and
*ensure the fan is cleaned of dust buildup, along with the HS fins.
The best way to combat instability issues and small OS quirks is to make sure you are running the most recent patches and updates. Use any automatic update features included with your flavour of Windows. They'll keep you on top of new security patches and updates, and its handled transparently, without user intervention.
PV
I thought a troubleshooting guide would be handy for the noobs or less technically minded members amongst us. The key to troubleshooting is efficiency: the quicker you can find and fix problems, the faster you can get back to work (or play). Its a given that at some time your computer will go belly-up. Its a cruel reality that computer owners have all learned to live with, and accept, beacuse thats just the way things are. The only way to approach troubleshooting your computer problems is through a systematic and methodical approach. Its a relativley simple process of elimination.
Modern computing has an ever-growing list of things that can go wrong. With clock speeds ramping up and sofware becoming more complex, there are literally thousands of errors that could detail your session in front of the screen. With that in mind, it's less important to know how to fix, say, obscure error 4137 than to have a solid troubleshooting procedure down pat.
Here is the method by which I troubleshoot my own personal machines, its recommended that you adopt something very similar.
Step 1. Playing dead
You've just sat down at the PC to get some work done, pressed the magic button on the front panel, and nothing happens. There's no LED letting you know that that the machine is in the throes of booting, and you can't hear any fan noise. Before panicking, there are a few simple checks to go through:
*verify that juice is getting through to the systems power supply unit (PSU) and that its set to the correct voltage, and
*sniff the air behind the PC. Power supplies quite commonly go south, and when they do, they give of a telltale aroma of burnt capacitors and circuit boards.
If a smell is coming from the PSU vent, you've probably overloaded it and it couldn't take the strain. Alternatively, it may have just died of natural causes/old age or an accumulation of dust and wear and tear. A new PSU isn't that expensive , but you need to purchase a reputable brand, for example: Antec; Tagan, Enermax; OCZ (a little overkill if you aren't oc'ing, there are cheaper available). PCnerd2357 has posted a cool little guide for choosing a replacement PSU here.
Make sure the new PSU you put in has an output in watts equal to the previous one. Most basic PC's can get away with a 300W unit; but if you are running multiple hard disks, a current generation processor and a modern graphics card, you are better off going for a 400W unit or higher. Pls try and choose a brand name PSU, instead of opting for a generic no-name brand. XMS has included a really handy PSU calculator here. After replacement, turn the PC on and it should boot without error. Should your PC's fans still refuse to spin, chances are that:
*it may be the PSU again;
*a small likelyhood it's the motherboard;
*your power button on the PC itself (I personally have encountered this, although rare on quality cases)' or
*you may have dislodged a connector accidentally.
#Some other handy guides, for suggested browsing:
FragTeks guide to jumpstarting a PSU- here.
FragTeks guide to testing your PSU rails- here
Tom's hardware have a really cool PSU stress test- here
If the power seems ok, you have to start going through a list of possible faults, working back to isolate the root cause.
Open Heart Surgery
Start by opening the PC's case. If you have recently replaced your power supply, examine the motherboard, paying special attention to the the cluster of tall silo-shaped capacitors arrayed around the motherboard's CPU socket. These are generally responsible for regulating the voltage and current to your slots and CPU socket. If you have blown the PSU and sent a power spike down the line, the capacitors will bulge at the top, indicating a fatal surge.
# Note: there is an interesting article here, relating to other causes of problems with capacitors. Problems mainly associated with P4 motherboards.
The only recourse is to pray that the spike hasn't made it beyond the motherboard to your HDD system or expansion cards. The components will have to be pulled out and tested individually. The best bet is to either test them in a friends computer, or take them to a reputable reseller and get them to test them for you. If thePSU powers up (with CPU and GPU fans) but nothing else happens, there could be a problem with the motherboard, CPU or RAM. If the PSU is fine but nothing happens when you boot-no light on the monitor and no warning beeps-its generally the motherboard that isn't functioning correctly. Just be sure to eliminate other possibilities before you throw it out.
Shuffling Chips and Cards
A faulty memory module will often halt a computer during the boot, so pull out the RAM sticks one-by-one and try to boot with different memory configurations. If that doesn't work, pull out all your expansion cards (save the video card) and turn the power on. If the machine boots, start replacing the cards one-by-one to isolate the faulty device. Sometime the peripheral component interconnect (PCI) cards can work loose from their motherboard connection, and pulling them out and replacing them is enough to enable the PC to boot.
# Note: just remember to start with a minimal setup and replace components, until you find the fault.
Working Loose
If there's obviously nothing wrong with the RAM or expansion cards, take a look at the connections inside the PC. Disconnect the drives and check the IDE cables for any obvious signs of damage or wear. Reconnect each one, trying to boot at each stage. If these tricks don't work, take a closer look at the motherboard and CPU. Pull them out and test them individually (if you have access to alternate, compatable hardware). If not, ask your local reseller to run motherboard and CPU tests. It shouldn't cost more than a few dollars.
Step 2. No signal to video card
When you turn the power on and your hard drives spin but your monitor remains in standby mode, there are only a few things that can be wrong:
*a cable has become dislodged at some stage, so check the connections between the video card and monitor (if possible try the monitor on another machine or use one that you know is operational);
*are there any error beeps when your machine powers up? If so check your video card. Pull it out of the AGP/pci-E slot, reseat it and try again. If possible try it with another card that you know works.
If the machine is silent when you first boot it (excluding fan noise), its almost certainly your motherboard is causing the problems.
Step 3. The Post
If the PC is powering up enough to emit a series of beeps, you've made it to the power on self test (POST). And at least the motherboard is functioning correctly, or at least ok enough to try to let you know what is wrong. When a machine is turned on, the first job of the basic input/output system (BIOS) is to perform the POST, a diagnostic program that checks the hardware. Technically speaking, this occurs before the boot procedure. The PC speaker is used to warn of the error because the POST executes before video is initialised. Look in your motherboard manual for how to interpret the series of warning tones, which vary from one manufacturer to another. For a generic rundown of POST tones for common BIOSes, go to http://www.pcguide.com/ts/x/sys/beep/index.htm . The POST tests many individual components including DRAM refresh, system timer, processor, keyboard controller, cache memory and video memory. In the case of boards with an AMIBIOS, continuous beeping indicates a problem with either the system memory or video controller. After checking the tone pattern with your motherboard manual and finding the cause of the fault, fixing it can often be just replacing a faulty RAM module or inserting a new video card.
Step 4. Putting the boot back in
Your PC can come up with myriad errors before being able to load Windows or any other form of OS. Here's a rundown on the most common problems that might prevent you from booting Windows, and how to fix them.
Safe Mode
msconfig utility to boot into safe mode
First, attempt booting Windows in 'safe mode', which loads a minimal set of drivers. Autoexec.bat and config.sys are not accessed and most of the Windows registry is ignored. Press F8 during the initial boot process to load the boot menu. Select 'safe mode' from the options list and hit Enter.
You can also opt for step-by-step confirmation to isolate an individual line that may be at fault in the autoexec.bat or config.sys files. If there's a problem with a setting in the registry or device drivers, choose the 'safe mode' option that loads the Windows graphical user interface. From here you can make the necessary changes to remove the source of the boot failure.
Missing Files
One of the most common error messages in Windows 2000 and XP machines is "NTLDR is missing. Press any key to restart". It signals a fault in one of three files: ntldr, ntdetect.com, or boot.ini. This fault is sometimes caused by an out-of-date BIOS, which can be corrected by a flash update.
#Note: Pls check with your motherboard manual or manufacturers website for how to flash your BIOS-but be careful. If done incorrectly, it can corrupt the BIOS and render your machine unbootable.
One way to get around the NTLDR error message (after checking your BIOS version) is to use a boot disk containing the appropriate files and replace them as necessary. The disk can be made as a precaution while your machine is still healthy, or belatedly on another machine. For details of how to make a boot disk under Windows to suit FAT and NTFS partitions, see the support article on the Microsoft website http://support.microsoft.com/default.aspx?scid=kb;EN-US;301680 . The preferred method is to let the original install cd for Windows 2000 or XP do the hard work. Boot your PC with this cd in the drive and hit R to enter the Repair Options page. Press R again, and when the prompt appears for selecting a repair option, press M. Now hit the up arrow a couple of times to select Verify Windows system files, and Enter to proceed.
After you have made the selection, move down to Continue and press Enter. You'll be prompted to insert an emergency repair disk. If you don't have one, press L to receive a message telling you where Windows is located on your HDD. All you have to do is press Enter and Windows will automatically make the repairs. On completion, you should be able to reboot the machine to Windows as normal.
XP's Fatal Stop Error
When installing a new piece of hardware under Windows XP, there is always a chance that the OS won't boot. You will receive a fatal stop error and one of those ominous blue screens just before launching the graphical environment. This is actually part of Windows XP's hardware tracking. When calling MS and activating XP, a list of the hardware in your machine is drawn up. This is cross-referenced at boot-up with the saved configuration. If a number of changes are detected, a fatal error is indicated. It isn't a given that you'll have to reactivate Windows. It depends on how much has changed. Upgrading your CD-ROM is unlikely to cause a boot to fail, but changing the motherboard is almost guaranteed to do it. This is because of the motherboard's individual components maintain separate entries in the Device Manager
MBR Misinformation
Being confronted with the message "Missing operating system" or "Non-system disk error" was relatively common under DOS and Windows 95, but they are rarely found in the newer versions of the OS. They mainly display if the MBR (Master Boot Record) doesn't contain the correct boot information or if there is no active partition on the drive. The boot sector is therefore invalid and needs rewriting. Below there are instructions for "fixmbr and fixboot", when using the recovery console to rewrite a boot sector.
Windows Recovery Console
For hardcore troubleshooters, the Windows Recovery Console is one of the most useful inclusions in Windows 2000 and XP. It grants limited access to FAT, FAT32 and NTFS volumeswithout booting to a full blown Windows environment. It's often used to perform disk maintenance or make basic changes to system files, as the user is equipped with a powerful yet minimal set of tools.
#Note: Remember, you'll need Administrator rights on the broken machine before you can use the console. This is designed to protect the data caught on NTFS partitions. Its possible to make devastating system-wide changes through the misuse of the Recovery Console, so be wary. Should you be unsure if the OS uses a file, err on the side of caution. Don't fiddle...you have been warned!!!
Fixmbr and Fixboot
I'm gonna allow MS and their knowledge base support articles do the talking here.
fixmbr
fixboot
Disabling services
The Recovery Console can also turn on and off system services executed at startup. If a particular device or service is causing errors, try disabling it and restarting the computer. You can use the listsvc command to display all the services or drivers that can be disabled, while the enable and disable commands set the start_type values for each service. Each service or driver can be set to one of:
SERVICE DISABLED, SERVICE_BOOT_START, SERVICE_SYSTEM_START, SERVICE_AUTO_START or SERVICE_DEMAND_START. Typing disable <service-name> will turn a service off. Entering enable <service-name><start_type> at the console will set the start_type value to whatever you specify. After you have made all your changes, type exit at the prompt to lock your changes, and reboot your PC.
Recovery Console Commands
Windows 2000 recovery console commands
Windows XP recovery console commands
Step 5. Windows Boot Errors
After you have managed to get your PC booting into Windows, you're halfway home. But Windows itself can cough up all manner of errors during the boot process as its initialising drivers and accessing the registry. When you are troubleshooting an application, pay close attention to the error messages. Note down what you did to generate the fault, only with this information can you start to draw up a list of probable faults.
Device not responding
If you get a Device Not Responding error when you load Windows , the first thing to do is ensure you have the right driver installed:
*open the Control Panel and click on the system icon. Select the Hardware tab and click on the Device Manager button to launch the manager. Any devices with errors will display with either an exclamation or question mark beside their entry;
*double-click any malfunctioning device to open the properties window. In the general tab you will be able to read a description of what is wrong with the device. Usually the problem will be caused by either a missing driver or a hardware conflict. In the case of the former, select the Driver tab and click on the Driver Details button to gather information on the file and version of the driver in use;
*check the manufacturer's website for the appropriate driver with a higher version number than the one you are running and install it using the Update Driver button under the Driver tab.
External Devices
Troubleshooting an external device is a two part process. You have to check the individual driver for the external hardware and the chipset driver to ensure that Windows can actually communicate efficiently with it. With regards to USB 2.0 and Firewire, you'll need to ensure that you have the latest patches and Service Packs for your version of Windows. Windows XP introduced USB 2.0 support in SP1, while Windows NT requires SP3 to provide high-speed USB functionality. Firewire support was rolled into the boxed versions of Windows XP and 2000, but later SP must be installed before its stable and reliable.
The Registry
If you are getting all manner of startup errors pertaining to half installed software packages or missing DLL files, the key to fixing the problem requires a trip to the registry. The registry is a database that stores your Windows settings and options for installed software. Every Windows system setting for your PC resides in the registry, from applications installed to screensaver and desktop wallpaper settings.
Windows 9x-based machines have two registry files, named USER.DAT and SYSTEM.DAT, which are stored in the Windows folder. Windows 2000, XP and 2003 maintain separate registry files for each user.
Over a period of time the Windows registry becomes clogged, with all the programs you install adding their own little entries to it. Theoretically when you uninstall a program its registry entries are erased, but this often doesn't happen. Over the course of several years of installing and removing applications, the registry winds up full of redundant entries, which in turn impact on performance, or in a worst-case scenario, produce errors.
One way to go ahead and fix any unwanted entries is to use a dedicated registry-cleaning application like RegCleaner- http://www.worldstart.com/weekly-download/archives/reg-cleaner4.3.htm , but it can also be done manually.
#Note: bear in mind that playing with the registry and deleting keys can be potentially harmful to your machine, so be sure to backup the registry files before you begin.
There are six main branches, each containing a specific portion of the information stored in the Registry. They are as follows:
* HKEY_CLASSES_ROOT - This branch contains all of your file association types, OLE information and shortcut data.
* HKEY_CURRENT_USER - This branch links to the section of HKEY_USERS appropriate for the user currently logged onto the PC.
* HKEY_LOCAL_MACHINE - This branch contains computer specific information about the type of hardware, software, and other preferences on a given PC, this information is used for all users who log onto this computer.
* HKEY_USERS - This branch contains individual preferences for each user of the computer, each user is represented by a SID sub-key located under the main branch.
* HKEY_CURRENT_CONFIG - This branch links to the section of HKEY_LOCAL_MACHINE appropriate for the current hardware configuration.
* HKEY_DYN_DATA - This branch points to the part of HKEY_LOCAL_MACHINE, for use with the Plug-&-Play features of Windows, this section is dymanic and will change as devices are added and removed from the system.
Each registry value is stored as one of five different data types:
* REG_BINARY - This type stores the value as raw binary data. Most hardware component information is stored as binary data, and can be displayed in an editor in hexadecimal format.
* REG_DWORD - This type represents the data by a four byte number and is commonly used for boolean values, such as "0" is disabled and "1" is enabled. Additionally many parameters for device driver and services are this type, and can be displayed in REGEDT32 in binary, hexadecimal and decimal format, or in REGEDIT in hexadecimal and decimal format.
* REG_EXPAND_SZ - This type is an expandable data string that is string containing a variable to be replaced when called by an application. For example, for the following value, the string "%SystemRoot%" will replaced by the actual location of the directory containing the Windows NT system files. (This type is only available using an advanced registry editor such as REGEDT32)
* REG_MULTI_SZ - This type is a multiple string used to represent values that contain lists or multiple values, each entry is separated by a NULL character. (This type is only available using an advanced registry editor such as REGEDT32)
* REG_SZ - This type is a standard string, used to represent human readable text values.
Step 6. Stability Issues
If your machine is crashing randomly, you'll have to do a little more work. A possible cause is a faulty RAM chip. Try pulling out the RAM modules one at a time, booting the machine between each change, and keeping an eye on the machines performance. If this makes no difference, an overheating CPU could be causing the error. The most obvious sign that your CPU is cooking itself is a tendency for the PC to reboot at seemingly random moments. Generally it happens when the PC is under load because it warms up as more tasks are placed on the CPU. One of the trickiest things about troubleshooting a heating issue is that by the time the PC reboots, the processor has often cooled enough to enable it to start normally. The machine will be perfectly stable again until the CPU is stressed again. The best way to fix this is by:
*ensuring the HS is firmly attached to the CPU;
*re-apply thermal grease (Arctic Silver) after removing the old paste, and
*ensure the fan is cleaned of dust buildup, along with the HS fins.
The best way to combat instability issues and small OS quirks is to make sure you are running the most recent patches and updates. Use any automatic update features included with your flavour of Windows. They'll keep you on top of new security patches and updates, and its handled transparently, without user intervention.
PV
