I use two free spyware products, Spybot & Lavasoft Ad-Adware. Running these two will solve all spyware and pc ads problems
If you have a problem with your webpage being hijacked run "hijackthis", however be carefull as this tool deletes items out of your registry, deleting the wrong items can cause problems with your PC. (You would usually only have to look at the top of the list and delete the line associated with the explorer home page.
Neil, May 2007