GA-Z68AP-D3 REV1 - Win7 startup hangs after installing HD 6770

[JulianHolt]

GA-Z68AP-D3 REV1
BIOS: F2
Core I5 2500 (3.3Ghz)
8Gb Corsair GX3M2A1600C9
WIN7 64
GV-R677D5-1GD
Latest Intel Chipset (9.2.0.1030)
SATA
Samsung Syncmaster 2333HD
Not over-clocked

I've been running the Intel HD3000 graphics (HDMI).  Just bought the Gigabyte HD 6770. Installed into the Pcix16 slot. Boots ok but display hangs on the Windows Startup screen - the point at which the system usually switches into higher res mode. If I switch the HDMI cable back into the onboard graphics then I can log into Win7.  Device Manager shows 'Video Controller (VGA Comp) as the second display adaptor.  I've tried installing the adaptor drivers (12-4_vista_win7_64_dd_ccc - latest version from ATI) (still using the onboard graphics) but Win7 'blue screens' & reboots during the install.
I've installed the HD 6770 into a different Pc and it works fine.
I'm thinking there is either something wrong with the Pcix16 slot or BIOS - maybe flash to F8?  Flashing the BIOS scares me...

I've fiddled with CMOS settings for onboard graphics - auto, enabled if detected etc - no joy.

Anybody any ideas?

I've spent approx 6 hours on this now....

thx

[Dark Mantis]

Hi and welcome.

Yes it might help to flash your BIOS to the latest version but first make sure that it isn't something else.

Have you made sure that the power cable is connected to the card correctly and the card is installed in the correct PCIE slot ? It should be PCIEx16_1.

Have you also installed thge drivers for the card ?

I know you say you have already che3cked but do make sure that you have the BIOS pointed to the right location for the GPU.

[sergio674]

Go in to BIOS advanced BIOS Features Onboard VGA should be on Auto.Advanced BIOS Features Init Display First set to PCIEx16.In windows go to system device manager Other devices and with right button on Video controller disable.
That is what I did with my Ati 4870 on Z68-UD3H-B3.I have latest BIOS update.