Run your resident virus program after updating it so it has the latest definitions, then run Adaware and Spybot, again updating them and running them in safe mode.
After that, run several web based scans. Pick at least three of the following if not all of them.Web based online Antivirus and anti-malware scans:
(these can be run regardless of whatever else you are using. You must use Internet Explorer to run these.)
Microsoft Full Service Scanhttp://safety.live.com/site/en-US/default.htm
Kaspersky Anti-Virus Web Scannerhttp://www.kaspersky.com/service?chapter=161739400#betatest
Panda Activescan (IE only)http://www.pandasoftware.com/activescan/co...n_principal.htm
Trend Micro antivirus and malware scan:http://housecall-beta.trendmicro.com/en/st...orp.asp?id=scan
Trend Micro antivirus European Edition (supports Mozilla based browsers)http://uk.trendmicro-europe.com/consumer/h...call_launch.php
Etrust Anti-virus web scannerhttp://www3.ca.com/securityadvisor/virusinfo/scan.aspx
online trojan scans here -http://scan.sygatetech.com/pretrojanscan.htmlhttp://windowsecurity.com/trojanscan
Windows Security Trojanscanhttp://www.windowsecurity.com/trojanscan/trojanscan.asp
Run at least one of the trojan scans in addition to the virus scans.
Set all of the scans you use to fix what they find.
You must use Internet Explorer for most if not all of these as they use Active X which Mozilla based browsers do not have.
If the result is not conclusively satisfactory I suggest you download Hijack This and following the instructions you will find at the following link explicitly, post your HJT log in the forum designated for it.
How to submit a Hijack This loghttp://www.bleepingcomputer.com/tutorials/how-to-post-a-hijackthis-log/http://www.bleepingcomputer.com/forums/How...s_Log-t956.html