Do you have AVG? If so, run its full rootkit scan which will only take about 5 minutes. If not, go here: http://www.safer-networking.org/en/spybotsd/index.html
- download Spybot Search&Destroy, right click on the icon and Run As Administrator. Update it, *Do NOT scan yet* - boot your PC into safe mode. Right click Spybot again and once again run as an Administrator, run the scan and remove anything found. After that, reboot your PC and run Housecall by Trend Micro here: http://housecall.trendmicro.com/
run it and again remove anything found.