This morning I found my PC is "contaminated" by "Spyware" ad, URL, etc. Whenever I reboot the PC, it pops up a windows saying "your computer may be affected by attempted attack. To protect.., please download Spyware software...". Then close this windown, it still pops up a browser window showing the download page. I close that one and open a new browser, the Spyware page shows up again even I set the "homepage" to "Google" !
I also notice on my desktop there are two icons for "Spyware" I permanently drop and clean them in trash bin, and reboot PC. It doesn't help.
And whatever you do, *don't* download the spyware remover that is being advertised !!
Ad-aware is good. I also recommend it. You may also want to try "SpyBlaster" by JavaCoolSoftware. It isn't a spyware remover. What it does is configures your browser with all the known bad web pages and activeX controls to block them.