Z68A-D3H-B3: Windows won't load after a new GPU installed

[anzo]

Board: Z68A-D3H-B3
CPU: Intel i5 2500k
RAM: G. Skills 8GB
GPU: XFX 6870 1GB
PSU: Cougar SX 850, 850W

Windows would get stuck at "Starting Windows" screen after I snapped on the GPU.
But it boots fine without it.  I already tried the GPU on other PC and it's working fine

What could possibly cause such problem? could it be the intel graphics chipset causing such problem??

Thanks

[Dark Mantis]

Hi

It could be down to power. Your PSU sounds powerful enough but I am not familiar with the make and so it might be  nowhere near that actual output. How old is it ?

Have you got the BIOS updated to the l;atest version ?

Try clearing the CMOS before installing the GPU. follow these instructions exactly.


Remove the power cable from the mains supply and then press the power switch on the case for a few seconds just to drain any residual energy in the PSU capacitors.

Once done remove the motherboard battery for at least one hour before replacing it.
 
Next plug back into the mains supply and boot.
 
You will now need to enter the BIOS by pressing DEL and load Optimised BIOS Defaults.

Make any other changes to the BIOS settings to suit your self like disabling the floppy drive, disabling the full screen logo and making the HDD the primary boot device and then press F10 to save and exit.

[anzo]

Yes I have updated the BIOS
and Why clearing CMOS might help??
Thanks