The very first thing people should do when their computer exhibits any strange behavior at all is do a thorough scan with both an antivirus program and an antispyware program. If you have the option of doing a light scan or a "complete" scan, choose complete. If your antivirus program has the option, do a boot time scan. Sometimes I even go so far as to install and run more than one antivirus program (there are several free options available for download and I'll talk about them at the end of this post) because different programs often catch different things.

Note: You should only have one antivirus program on at a time as they can work against each other. I don't think it matters with antispyware programs though.
It never hurts to do these scans, and even if you think your problem couldn't possibly be due to spyware or a virus, run the scan!! If nothing else, getting rid of those tracking cookies could improve browsing speed.

If the problem persists after running the scans, a great resource to use is the GeeksToGo forum. This forum is run by volunteers that spend all their time helping users fix their computers. The site has detailed malware removal guides, and you also have the option of running a diagnostic tool and posting the log on the forum. Then a volunteer will review the log and help you fix whatever problems are found. I love this site!!

They also recommend various free antispyware and antivirus programs (I've been using Avast and SuperAntiSpyware for a couple of years now myself).http://www.geekstogo.com/forum/topic...ware-software/

Here is a link to their site that explains how to post to their forum and run the diagnostic: http://www.geekstogo.com/forum/topic...leaning-guide/

Just one final tip - it could make your scans run faster if you run a program like CCleaner to clean out all your temp files and cookies. Not a bad idea just for general computer maintenance either. It's a free download here: http://www.piriform.com/ccleaner

Good luck!
Nerdy