New R9 280x drivers aren't installing correctly. Unsigned?

So I just got a new gigabyte R9 280x (upgrade from a 460) and when trying to install the drivers I get a unsigned drivers warning from windows and I can't seem to fix it. I've tried disabling signature enforcement on windows startup and after installing/rebooting still doesnt work.

This is an issue caused by Windows update KB3004394.

Uninstall windows update KB3004394, and re-install the drivers.

@BSC14: Attempting this right now will report back with the result.

EDIT: Thank you so much man!! You actually completely saved my night from being a shitty one!

Good to hear.

Had the same problem, glad to hear everything is working fine now.