Have you tried restarting your computer into SAFE MODE and see if you can access any files? You can also try to run your anti-virus in that mode to see if it can remove the virus.
Which version of Windows do you have?
Accessing Windows XP Safe Mode EDIT: Just as a quick note, my Dell laptop requires F12 (not F8, as the article mentions), to access the Boot Menu.
EDIT2: Also found information for Vista (in case that's the operating system you're using):
Safe Mode in Windows Vista EDIT3 (last one, promise
): make sure you run a virus/malware scan on the external hard drive where you copied the files to, to make sure you didn't contaminate it.
malu