Unfortunately I dont think there is an easy fix for a corrupt regisstry.
If you still have your windows install discs you could try running "sfc /scannow" from the cmd prompt. This will verify all system files. Some malware will purposely trash the registry on the way out.
But a restore is most likely going to be in order. Even if you do manage to get all of your programs to run again system performance is going to be shite.