Please forgive me if you have already tried this:

1. Update your Ad-Aware SE and NoAdware
2. get Spybot Search & Destroy and the trial of Ewido
3. get SwatIT

Run them all in SAFE MODE

Frequently this stuff cannot be removed because it is active when you run the countermeasures.

The trial of Ewido will revert to a free, fully functional on demand scanner that you can update. the only difference to the pay for version id the interactive protection.

Whilst in safe mode and before you run the countermeasures, be sure to empty your temporary files, cache and history. Don't forget to empty the Java Cache, in fact it would be a good idea to disable java caching.

Use the "tools" bit in Spybot's advanced mode to look at plug-ins, BHOs (browser helper objects) and your "Hosts" folder. Delete anythiong that seems related, or you don't understand...........this is safe because if you really do need it you will be prompted to re-install next time it is required

Good luck...........please keep us informed

EDIT: SwatIT takes a long time to run.................it is very thorough. Ewido currently looks for 87,000+ nasties, so is worth a try.