Download AVG Free AV. After you've installed it, update it & then scan your computer...see whether that finds a nasty & solves the problem. There's a link for download in the thread below.
http://www.gnutellaforums.com/downlo...s-options.html

If that doesn't fix things for you, check the thread below for more fixes to try. If you're still stuck, this thread has links to sites that offer specialised help for malware problems
http://www.gnutellaforums.com/genera...s-options.html

Always make sure that you're using a good AV program. Keep it updated & use it to scan all files that you've downloaded before you open them.