This was revived, but I had the same problem and fixed it!
It was anti-spyware 2009. What a pain!!!
You have to go into your C: drive and find the files that were loaded by anti-spyware. There was one that will likely be there, but I don't remember the name. (I got this information by checking google for antispyware 2009 and found a bulletin board where someone had done this.) If you know the date that you likely got infected, it helps. Note any .exe files that are dated that date. Go to task manager, on the application screen and end task for those files. You can then go back and delete the files.
I did this over a month ago and have had no problems since. (and yes, the wal-mart ad talking to you is just plain annoying!!!)