New build, very weird problems

OK - I've had my new build up and running for a week, no problems. Today, however, something weird happened. I put Office 2007 in the CD drive and waited for it to auto load. It ran, but nothing happened. So I went to my computer, and it was a blank screen trying to load. Nothing loaded at all after three minutes. I tried to end it and it wouldn't end. I tried restarting, and when I clicked "restart" it just sat there. So I hard reset...

Next time, I type in my password to get into Vista, and all I get is a black screen and my mouse pointer. THAT'S IT. So I reboot again, this time in safe mode.

Safe mode loads fine, and all seems well.

Tried rebooting to normal windows. It loads fine this time, but when I click on Firefox, nothing happens. No programs were loading. SO I reboot AGAIN...

This time, all works fine. EXCEPT: My computer seems to be significantly slower. I re-ran my PCMark05, and my score went from 6300 to 5900 in one day. My 3Dmark score was ABYSMAL. I averaged 10 FPS.

I tried playing Halo 2 which played beautifully earlier, and it was so choppy I had to stop. When I exited the game, Windows froze completely and I had to hard reset.

WHAT THE HECK IS GOING ON??? Everything is so unstable, and I haven't even overclocked yet! I've installed a bunch of programs over the last few days, but I know what I'm doing and everything installed fine.

I know these are vague issues, but does anyone have any advice? I'm crushed this has happened...

Try doing a dual boot of Xp and Vista. I use Xp as my main OS mainly because everything just works like it should. I have Vista Prem on my second Raptor basically for future use and to tweak and play with until it becomes less buggy updating as necessary. This way you can play all those glorious Direct X10 games coming out and still revert back to Xp when your not gaming and want to do other things virtually bug free.