VIRUSES ON SYSTEM(AFTERMATH)

i recently noticed that my friend was encountering a problem with his newly purchased computer and he was not able to access most of his files and pictures,i found out that he was not using any antivirus program and when i installed avast on his system and performed the boot time scan,avast detected about 112 .exe files as infected which includes the files of nero,jet audio and various other software,so his computer is totally spoiled by the attack.
The viruses were
Win 32:passma
Win 32:VB CD
and mostly passma was found.
now whenever he tries to fix a new cable internet connection to his LAN card port, the system restarts and i formatted his C drive hoping the problem would go away and it did!
please tell me what had happened

Recovering from a very deep infection is not easy… maybe starting all over again, from the scratch, will be easier than trying to fix them…

Anyway, maybe overinstallation can solve the problem and you won’t lose your programs, settings, data, files, etc.
Just choose ‘Repair’ installation of Windows and install ‘over’ the old installation.
http://support.microsoft.com/default.aspx?scid=kb;EN-US;315341
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q314058
http://www.webtree.ca/windowsxp/repair_xp.htm

thanks!!!
:wink: