If you are safe, Keep the windows firewall up and stay away from weird sites, Don't download dodgey items and delete emails that obviously are spam then you wont need an anti virus program.
I haven't had an anti-virus program for over 4 years now and I am constantly on the net, Downloading various things, Drivers, Game mods etc... and I haven't had a single virus.
I know this isn't an answer to your question but the only protection ones computer needs is common sense.
What AV are you running?
Do you even have a license with any of these AV companies?
Try downloading a free one. Though not the greatest by far, this will work.
Microsoft Security Essentials
Reinstall windows. Get a new drive. Bye bye virus.
Hi livadi, sorry to hear about the problems you are having. Trying to cure an infection whilst the windows operating system is up and running can be very difficult and sometimes impossible as the infection is also running with all of it's defence mechanisms in place.
In my opinion the best way to go is to do a "boot time scan", as this scans your pc BEFORE windows and the infection are loaded. Have a look at this link.
http://www.squidoo.com/the-best-free-antivirus-rescue-cds
I personally have used the "bitdefender" cd with good results.
Hope this helps,
mArTyN
Try avast free antivirus. It was the best free one of 2013.