system
3
Hi,
the exact virusname and location (full path and filename + extension)
would be real helpful here… 
What WIN do you have ?
If 2000/XP: have you applied the Blaster/Lovsan/RPC-Patch (info: on avast virusinfo or almost everywhere here in the Board) 
Have you done a full scan in SafeMode (F8-Boot) ? then there should be fewer locked files…