try running legit anti-virus (Kaspersky, McAfee, etc.) or spyware removal (Spybot Search & Destroy). If for whatever reason you don't have any of these or they won't work, try this:
Free Virus Scan - Kaspersky Lab
it's a free, web-based scanner. it's very thorough and takes a while to run, but it found things that other scanners have missed. it will not physically remove the infected files, but will point you to their location so that you can manually remove them.