Mobo Splash Screen lock on new build

I have just build my first comp, and am having a few problems, and would appreciate some advice. My build is the following:

Intel Q6600
Gigabyte GA-P35C-DS3R
Patriot 4GB PC2-6400 C4 Extreme Performance (4x1GB) @ 2.2V
XFX Geforce 8800GTX 768MB
Western Digital Caviar 250GB S300 16MB 7200RPM
Lite-On LH-20A1S-15C DVD RW
Antec Nine Hundred Black ATX Mid Tower
OCZ StealthXStream 600W
XP upgraded to VISTA

Despite being a newbie, building it seemed relatively straight forward, although when I eeventually plugged it in - no video. I played around with the graphics card and it booted up ok. Installed XP, fine. Upgraded to Vista, fine, except a few resets that it said on bootup were unexpected.

Now Vista is installed, I can't get off the mobo splash screen on bootup. I chaged to CMOS settings slightly but nothing really significant, but have no idea why its suddenly not working.

Also, the video only seems to work intermittently when I take the Graphics Card out and put it back in. Any ideas what could be wrong?

Thanks

While StealthXStream isn't the same as GameXStream, it should at least work fine for a while. It's def. not generic crap.

Oh oh oh, you got 4 x 1gb, you gotta up the vdimm to specs. I'd say 2.1v tops.

You can tell whether a psu is good by looking at the outputs. In bios, go to system monitor, look at the voltages. The discrepancies should be within 5%. i.e. 5V should be withint 4.75 & 5.25. If any goes beyond 5%, the psu is not good. You have to look at them at idle & under load. speedfan is your friend. Also, use Gigabyte's EasyTune for the voltages.