Black Screen After Splash/Combo Fix/Vista

I ran ComboFix and now I have a black screen after I login at the splash screen. I know all of my programs and desktop are still there - I just can't access them. In Safe Mode with Networking I see my icons on the desktop on a black background. In Normal Mode I can only get anything to run by going to Task Manager to open it. In Normal I can download my email, but can't reply - system hangs. I have been able to update my AVG 8.0, which I could not do before I ran the ComboFix. Also in Normal I can't access the internet, but I can in Safe Mode. That's how I was able to send this message. Please help! This is the computer I use for my work and I really need it working normally.