I've been doing a lot of moving hardware recently (just got a new case), and booted up, then restarted a few times later with no problems. one time, though, out of the blue, I tried to boot up and my computer got stuck at the motherboard logo screen. I tried turning off the computer, clearing the CMOS (with a button on the back), unplugging all USB devices I had except my keyboard, and started it up. I got the motherboard logo, then a POST error message with a couple options I didn't really understand, but I chose the first one and my OS started up. I tried this again with the same results. any idea whats going on or how I can fix it?