I suggest you download Ad-Aware 2007 and Spybot S&D (they’re free), install them, update them and run them. If either one (or any anti-malware, for that matter) doesn’t seem to be able to get rid of everything it reports finding, try running it again in Safe Mode. Safe Mode often prevents malware from protecting itself.
Also, turn off System Restore to evict any copies of bad stuff that might be lurking there.
To get into Safe Mode:
1. Log out and reboot your machine.
2. When the machine starts the reboot sequence, press the F8 key repeatedly.
3. Select Safe Mode from the resulting menu.
4. When the login screen comes up, log in as Administrator. By default, Administrator has no password.
5. The machine will continue booting, but the Windows desktop will look different. You won't be able to see the Internet, for instance.
6. When you're finished, log out and reboot back into normal mode.
Note that even if the anti-malware programs get rid of the malware, they may not be able to reverse the effects. Search the Web for possible fixes.
Update and run everything regularly.
Good luck.