W32 / Virut experience

Long time never facing virus problem, until one day my friend ask me to help him to fix his PC. This PC came with very slow and cannot login. i restarted and try to login again and same problem coming. i suspect there is some virus there that may be destroy login application in WIN-XP. After take its hardisk and scan with AVG 9 and aha i knew it. yes its infected with W32/Virut virus. I ask my friend to perform clean install of WIN XP to get better and free from virus. He done what i said, but one of wrong step make this virus come back again, so terrible. Actually this virus still in drive D woah....finnaly i perform clean install of WIN XP and directly install antivirus there, after that install driver and application. and everything goes well. I said, i never facing virus experience anymore since i use linux. :)