i have a problem that i had since the previous build (i7 950, ASUS P6T SE, 12gb...). I changed build to i7 3770k, ASrock Extreme 4, 32gb, and i though that i would solve this thing. After a fresh install of Win 7 Ult. 64 bit, the shortcut Win + E still does not work, tho the registry entries are all good. And the ALT key acts like as if it is a togle on of button. I notice that in ADOBE programs (Photoshop or illustrator), if i tap the ALT to execute a shortcut command, i have to tap it twice to "release" the presue and use it to ZOOM in and out after holding it...
The thing is stil usable, but bothering tbh... especialy cos i can't open EXPLORER.
I have a Logitech G15 keyboard, wired through USB port, but as i said, it was already doing this before.
Does the keyboard have it's own drivers? Try installing or reinstalling those. Try using the standard windows keyboard driver. If none of that is working then it has to be a faulty keyboard, I can't see any other option to take there but replacing keyboard.