I just built a new pc using a AsRock Z77 Extreme 4 motherboard. MSI Frozr III 7950 video card.
It will not boot with the video card in the pc. Using the onboard video i installed windows. I tried both PCi 16 slots and still no boot, just a black screen. Any suggestions on whats causung this. I have an Antec 620W continous PSU
try making sure the mb bios is up to date..if it not a bios issue then it a power issue. check that the right 4/8 pin cable for pci power is connected to the mb and make sure if the video card has two 6 pin or two 8 pin power both of them are plugged in. if they are check your ps and the 12v line. some ps have more then one 12v line and sometime cant handle the load of a high end gpu.