We've had many threads concerning it, and the program Spybot is generally the best way to approach its removal. Spybot will probably detect many other hidden spyware installs as well.
You can follow the instructions from this link on installing, updating and running it. Be sure to accept all the updates except for the Language and PGP tools which you probably don't have a use for.
http://tomcoyote.com/SPYBOT/
You may also wish to give us a complete look at your startups and other configuration features using the program HijackThis and its integrated StartupList. You can do this either before or after you run Spybot. If problems continue after Spybot, definitely give us a look.
http://www.lurkhere.com/~nicefiles/
To use HijackThis, after unzipping it, run it and then click the "scan" tab. A log will be produced which you should copy/paste to a reply here. Then click Config > Misc Tools > Generate StartupList, and copy/paste that file here to the same reply.