Hi My pc was sick after years of using p2p softwares ... without real antivirus and antispywares.
I downloaded recently CWShredder, Spybot and ad-Aware (3 antispywares). These softwares are excellent and free. I recommand them to u all.
HijackThis can also help, particularly against the unwanted searchbars. But be prudent with that last one, it doesn't makes the difference between good and bad files, You have to make the choice ...