Trogen-Gen help

Hi all, my pc contracted a virus recently and I have not been able to get rid of it. Although Avast recognises the virus, it seems to be reinstalling as it reappears when i put it in the chest or delete it.
Please help me because the virus may have stopped my antivirus programs from downloading updates, and i can not get to windows related web sites either…

I have Winxp sp3…should i first turn off windows recovery thing and then post a hackthis log? do i generate the log in safe mod?

Thanks for the help.