Run HijackThis and check the following:
O2 - BHO: Spybot-S&D IE Protection - {53707962-6F74-2D53-2644-206D7942484F} - (no file)
O2 - BHO: (no name) - {7E853D72-626A-48EC-A868-BA8D5E23E045} - (no file)
Click FIX CHECKED
Download
SilentRunners.vbs
Unzip it to a permanent folder.
Read here how to unzip/extract properly:
Help removing and preventing spyware - Compressed folders XP
Start
SilentRunners.vbs
When your antivirus is giving an alert, do not block this. Allow the script.
When the scan is done, notepad will open with a log in it. Please close this again.
I'll need that log later.
Normally that log is saved automatically in your silent runners-folder.
Post the log it created.