Download CWShredder:
http://www.spywareinfo.com/~merijn/files/CWShredder.exe
Run and hit the ->fix tab to fix all found problems
CWS takes advantage of security holes in windows so you should install all critical as well as hotfixes available from windows update.
Then repost a fresh Hijack this log .
Download 'Hijack This!'
http://www.spychecker.com/program/hijackthis.html and save it to a folder on your desktop.
Unzip, doubleclick HijackThis.exe, and hit "Scan".
When the scan is finished, the "Scan" button will change into a "Save Log" button.
Press that, save the log, load it in Notepad, and copy its contents here. Most of what it lists will be harmless or even essential, don't fix anything yet.