Gpu possibly not working right

So today I took my video card out to see how the intel hd 4000 graphics where just out of curiosity. I put my video card back in Plug the power cables in and every thing and try get get into windows 8 and it gets to the windows sign with the spiral as its booting then just goes blank. Idk what the hell is wrong. gpu is just what I think it is so this is where I'm posting. I have a sapphirregrade on 7950 FYI. please help 

If it comes down to it reinstall windows 8. If that doesn't work try windows 7. If that doesn't work its either not completely connecting in the PCI-E Slot, a Power rail went or its just dead (also try changing the pci-e power connector).

Ok If I reinstall 8 and I have a restore point can I are install from it?

Oh another thing could I possibly be a chip in my ssd failed?

Ok it started freezing on the 8 loa screen so I switched pic slots and it kept doing it now when it freezes it restarts the computer automaticly I really don't know why to do now.... I'm thinking its drive fmixture maybe?

Ok I ended up puttiintent hard drive into another computer and then back in mine and that worked.