Virus are a part of being on line. We all hope that our security software is doing its job. However it never hurts to check.
Some times the anti-virus lets something slip, instead of waiting for something bad to happen I scan my computers once a week.
Windows security .com offers a free Trojan scanner. It’s pretty good, and its free! [1] http://www.windowsecurity.com/trojanscan/
Another good site is  Runscaner [2] http://www.runscanner.net/ There are others Micro Trend is a great site as well.
Of course they are all going to try to sell you something, however getting the scan done is whats important here. Once you find something you can remove it.

There are many anti-virus programs out there, what I use and have been using for a while now is AVG free version. I then will run
a scan such as the one’s above. If you every get stuck on something always remember that Google and the Dog Pile searches are your friend.
There has not been any computer related problems that I have not been able to solve by doing a search.