If I want to completely clean up my computer I do the following, and it ALWAYS works:
first I download and run the latest version of "hijackthis" and run it and save the log file.
Then I go to "panda active scan" which is a wonderful deep-scanning program which you dont have to actually download... it does it all online.
Then I go to lockergnome and select "help" and "forums". Then I go to the general forum, and the "hijack this logs" subforum. There I post the results of both scans, beg for help and wait for a reply. There's a guy there called greyknight who is a systems analyst. he takes a day or two to respond but when he does he gives you complete instructions on how to clean your computer.
He is my saviour three times over so far.