Trying to build first PC

I've done enough updating on computers, with the various amount of troubleshooting, over the years to attempt to build a 'frankenstein' computer for a grandkid. New case (cheap aluminum one), motherboard (Abit), CPU (celeron), CPU fan, case fan, 450 W power supply, memory (512MB), and DVD burner. Reused video card (Geforce MX4000), soundcard (Audigy), monitor, keyboard and mouse, and hard drives (two 40 GB Maxtors).

I assembled the motherboard, CPU, memory, fans, other components into the case. Check and double connections and wiring. I power on, adjust the BIOS settings (boot order mainly, I have no floppy), and computer reboots, and promptly shuts down when it gets to loading Windows (my primary drive is bootable and has XP on it). Try several times, more checking and rechecking, still shuts down at windows load. After reboots, I get prompted to boot into safe mode, shuts down regardless of what I do. Every so often, after the BIOS screens, and prior to windows start, I get flashed a blue screen with text, but never long enough to discern what it thinks the problem is.

So, I uninstall everything and try applying components one by one. Nothing works, still shuts down. I put in the XP disk, it actually makes it to the blue setup screen, shuts down while loading. I put in a Vista CD, it gets to a loading screen as well, then shuts down. I'm currently using the motherboard monitor port, took out sound card and video card. I replaced the new power supply, thinking that was the problem. Same issue, put new supply back in. I took out and reseated the memory. I reinstalled the various case wires from the front features of the case (leads for reset, LEDs, power, etc.). I tried various combinations of the two drives (swapped master, slave; tried single drive as master, single drive as cable select). I tried replacing the IDE cables. I'm about out of ideas. Do I have a bad motherboard?? Thanks for any advice.

 

I put thermal paste--I applied the entire little syringe and smeared over the CPU. The heat sink (by Masscool) is square, there does not appear to be a 'correct way' to install. The pics on the box said to look for a 'wide' and 'narrow' side, but the device was square. I've disassembled and reassembled the entire thing twice, and did find that I had a standoff that was not lined up with a hole, and removed it. No change. I even attempted to boot off of Knoppix, with same result: a bunch of knoppix loading, almost appears ready to give me a prompt, and shut down. Very frustrating. Thanks.

 

Solved all due to you, etaf! Thanks.

Your assessment that it was a power problem took me to the one thing I hadn't re-taken apart--the CPU fan. I recalled that the cryptic instructions on the box said to orient the device via the 'wide' side. I didn't see any wide or narrow side--it looked completely symmetric to me--so i just installed it. When I took it apart and looked again, it indeed DID have one side that was slightly wider, which I did not have pointing in the right direction. So I rotated it 90 deg to line up properly, fired it up and everything worked fine! I've reassembled everything, installed the OS, and my grandkids now have their own computer. Thanks again!