Spyware...Makes me say very ugly things!
Maybe something that happened to me this weekend will be of use to you, so I will share this painful experience. I was happily using my computer when I noticed a new search tool bar on my explorer pages, and when I tried to delete it, it would not let me do it. Then when Norton ran my weekly scan, it informed me of adware that had found its way into my computer.
Suddenly ads began appearing over top of my web pages, I had this tool bar that wouldn't go away, my web pages were coming up slower and when I tried to delete the offending file, it kept coming back! I did not have any anti-spyware on my computer, so I began canvassing friends and asking their advice.
I tried Adaware, Spybot, and EZPestPatrol. Each one found numerous things on my computer that should be deleted (I am talking over 100). After the third or fourth scan, it was down to three or four and the original problem was still there! I was afraid I was going to have to wipe my computer to get rid of the obnoxious Adware.lop. But then a friend recommended the Microsoft Antispyware. So I downloaded that and it cleaned up a couple more files, but the problem was still there.
Then I noticed an Advance Tools button. I clicked on it and finally I was able to delete the offending tool bar! Then I went back in and deleted the adware file that Norton had pointed out to me (I had done this before, but it kept coming back). Then I emptied my recycle bin (something else I hadn't done before) and my problems were solved!
So, my advice is get a good Antispyware program and run regular scans of your computer before you get infected. If you already have a problem like mine, maybe my three days of trial and error will be of use to you. Good luck!