ClamWin: virus?

Please note that it sounds like you have some sort of adware, not a virus. ClamWin may be able to help you or may not. Also be aware that ClamWin is a file checker, not a system cleaner and will not be able to repair any changes that the Malware has made to your system. And it does sound like changes have been made. Depending on what ClamWin finds and you choose to delete you can render your system unusable. I would recommend that you get a more advanced Malware checking tool and consult with someone more knowledgeable. That having been said, the files you are asking about are located here:

You can download the latest definition files for ClamWin here:

http://www.clamav.org/download/cvd

You want to download the main.cvd and daily.cvd from that page:
http://db.local.clamav.net/main.cvd
http://db.local.clamav.net/daily.cvd

and put them here:
x:\{YourPath}\ClamWinPortable\Data\db\

AFTER deleting any files called main.* or daily.* that MAY be there already.

When run in default mode ClamWin will inform you of what it finds but will not delete anything, this may give you more information about what you might have and aid you in making decisions before running ClamWin in quarantining or removing mode.

Your proceeding with cleaning your system in this manner is highly risky and is not recommended.

Good Luck,
Tim

I would suggest trying Spybot SD. If you can install that on the infected computer and run it, you're probably going to find what is causing the problem. It is able to find and delete most problems.