If its an archive, more then likely the files are in a compressed ZIP/TAR file or compressed exceution file, you'll need to find and delete that file. You may be getting a false positive if its reading the files in a ZIP.
If this is something new then again, more then likely its something you recently downloaded and maybe sitting in a temp location somewhere. Get crap cleaner and clean the pc.
If youre getting more positives lately, try these
1. Use AVG
2. Windows Defender
3. Peer Guardian
4. Crap cleaner
5. Mozilla firefox instead of IE
6. Use the NOScript plugin with Mozilla. (its ad addon that stops scripts being run while browsing)
All links should be in clean PC post or easily found by google for, I havent had a virus in years just using the above and I would use the internet a lot.