again, thanks for the quick replies;
first of all pls see below a few of the BSOD error messages that I saved as time went on
plus have att a picture of the inside of the PC. Hopefully managed to point the camera at a useful bit

If not, let me know & I'll try again.
Might also be important (dont know) but I have 2 sticks of 2gb each of RAM, but when I look at System & Maintenance menu of my PC it can only see 2gb.
Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.0.6001.2.1.0.768.3
Locale ID: 2057
Additional information about the problem:
BCCode: c2
BCP1: 00000099
BCP2: 842A3F80
BCP3: 00000000
BCP4: 00000000
OS Version: 6_0_6001
Service Pack: 1_0
Product: 768_1
Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.0.6001.2.1.0.768.3
Locale ID: 2057
Additional information about the problem:
BCCode: c2
BCP1: 00000099
BCP2: 847BC7C8
BCP3: 00000000
BCP4: 00000000
OS Version: 6_0_6001
Service Pack: 1_0
Product: 768_1
Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.0.6001.2.1.0.768.3
Locale ID: 2057
Additional information about the problem:
BCCode: a
BCP1: 00000054
BCP2: 0000001B
BCP3: 00000001
BCP4: 827AFFE9
OS Version: 6_0_6001
Service Pack: 1_0
Product: 768_1
Problem signature:
Problem Event Name: BlueScreen
OS Version: 6.0.6001.2.1.0.768.3
Locale ID: 2057
Additional information about the problem:
BCCode: d1
BCP1: 00000000
BCP2: 00000002
BCP3: 00000001
BCP4: 881453D5
OS Version: 6_0_6001
Service Pack: 1_0
Product: 768_1