Windows 8.1 Start up Issues

Hello, I have been running W8.1 for the past few months with out issue. I ordered a 6970 from newegg, tossed it in my PC and did fresh install.
I get all drivers, software and games ect. ect. installed, then it starts locking up on the start screen. (Cant push anything to bring up the password screen). I have seen driver issues with the AMD ACHI included with catalyst, I have seen start up issues with updates and a little bit of everything. I really don't want to do ANOTHER fresh install after 3 tries...
I do no have the ACHI driver from cat. so I cant uninstall it, and if I do I dont see it.
I have tried removing updates to no aval.
Now Im stuck and cant restart my PC. And start up repair says it can't fix the issue, whatever it may be.
Hopefully someone will be able to help. Thanks.

Does it boot up in safe mode? Safe mode shouldn't load any video card drivers just the basic Windows vga ones. Its what I've always done to get around video driver related boot issues.

Yes I have ran on Safemode, pulled all drivers and its still doing it, Im seriously at a loss as I have never seen this before. I am running the exact same thing, all I did was replace the GTX 460, with my HD 6970 and reinstall windows....

Try pulling the 6970 and put the 460 back in. See what happens.