I had a similar situation, but found a slightly different solution by changing my video card temporarily:
Symptoms: After the 'welcome screen' I got a black screen with just the cursor (no My Computer icon). It would, however, let me run in Safe Mode w/networking.
I tried these fixes, in roughly this order:
1) Reset BIOS to default ...no change.
2) Tried Prevx Fix in Safe Mode ...no change.
3) Ran full virus scan in safe mode using Avast Antivirus ...returned one infected file [arg318495.exe or Win32:Crypt-MHR] MHR = Malware Hash Registry ...Successfully deleted, but still no change!
4) Removed recently installed video card, and replaced with old card. I do not believe the new card was a cause, but it prompted Windows to notice a hardware change, and ask for repair/restore selections during startup. After choosing 'system restore' my desktop loaded normally, and I switched the video cards again..