What program did you use to remove the "nastyware"?

Can you boot in safe mode? If so, try this:

Have a look in threads in our security forum for instructions on how to download and run HijackThis, Ad Aware, SpyBot, and CWShredder.
Download those programs on a working computer and burn them to CD. Start your duff machine in safe mode, and run the utilities from there to see if that clears things up.

Since you mention that you've already been infected, I'll move this to the Security forum...

Try the following & see if it works. download and run this program. Once done, please reboot. See if you still have problems.
How did you clean it out? Did you make backups first?