Google redirect virus

[megery]

I believe my computer has the google redirect virus. I have all the symptoms: my computer is really, really slow, any search engine redirects me to spam ad sites, random pop-ups, strange error messages. I completed the 8 steps for virus removal, and the SuperAntiSpyware scan showed a trojan affecting several files. Since that's been removed, I haven't really noticed any symptoms, but I'm not entirely sure that the virus is gone. Please help!