FFS, go in safe mode, run all your virus scans from the ADMINISTRATOR account in SAFE MODE, and you will have total access to delete the files. Also, if you are running XP, before you go into safe mode, right click on the "My computer" Icon IN THE START MENU, and do this:
Right Click > Properties > System restore tab at the top > The check the "turn off system restore on all drives" at the top.
Then go into safe mode, and run virus scans as I said.
A guide for starting in safe mode:
http://rsforums.org/forums/showthread.php?t=376