Windows 7 won't open all any installed applications

I was stumbling on firefox when all of a sudden my computer shut down. Upon reboot it would not allow me to run any .exe programs. It won't let me run them even if I click on them right at start up. I can open folders and start task manager, but other than that I can't do anything. Reboots take forever and don't work sometimes. I already updated all the registry files also and restored it and neither method worked.
Any help would be greatly appreciated.

Also a side note, watching taskmanager lets me see that the computer is opening processes with an .exe file type but won't allow applications at all.

yep I already did that. First with the exe option, and then with every other one. And i did it before and after system restores and restarts. It didn't work anyway I tried it.

There's a virus going around that shuts down the Action Center, turns off any AV software you have, and when you try to run an EXE it says something like "What do you want to use to open <programname>?" The only way I was able to recover from it was to boot off my AV DVD (I bought a retail version in the store, so I had a disk), and after cleaning just to be safe I used the oldest Restore point. After booting seemingly clean, I ran a full scan on the system. I've been clean ever since.

From what I can tell, I was infected on the fly from a banner.

to search53, mine doesn't display any sort of message, just pretends to load for a couple minutes and stops. also thank you lehnerus2000 i'll have to check that out.

I was stumbling on firefox when all of a sudden my computer shut down. Upon reboot it would not allow me to run any installed programs. It won't let me run them even if I click on them right at start up. I can open folders and start task manager, along with defragment and disk clean up, but i can't open any installed programs. Reboots take forever and don't work sometimes. I already updated all the registry files and restored it and neither method worked. I have restarted it and also installed the .exe registry file about 3 times.
Any help would be greatly appreciated.

Also a side note, watching taskmanager lets me see that the computer is opening processes with an .exe file type but won't allow installed applications at all.

I have avg, malwarebytes, lavasoft ad-aware, spybot search and destroy, and spyware blaster. The only problem is that I can't run any of them, even if I load a usb with them and write an auto run file.