I Used Spybot, Lavasoft ,webroot on my computer to search for Spyware, Adware.

I have noticed over the last two days that when i search on Google and Yahoo the first 4-5 results are all porn type sites , and they are the same sites coming up no matter what i search for or whether i search on Google/yahoo.

I even removed IE explorer and installed Firefox and the problem still happens.

Has anybody experience this problems ? if so can anyone help .