Computer wont run windows, other issues.

Ok I know this isn't exactly windows 7 discussion, but I have tried everything and figured I should come here for help, I was going to just replace the motherboard, but it's a friends computer, and they can't afford to replace it.. so first of all here are the specs.

ECS RS482-M754 motherboard
Socket 754 Athlon 64 3200+
1GB DDR 400 RAM
Nvidia 6200TC

Ok, so when I started working on this computer it was running Fedora, and it's biggest problem was random shutoffs, and slow performance. I found out the CPU was getting up to 90C, causing the computer to shut down to protect itself. I took off all the heatsinks cleaned them, and applied new thermal paste. It helped a lot, but was still running way too hot.. So I went back to the BIOS and discovered the CPU was overclocked by just 200MHZ, but had a MUCH higher voltage than it should have. this was with it's automatic settings.. This is when I start to realize I'm dealing with the motherboard from hell .. Ok so I fix that issue, and my friend wants me to install windows. I stick in the XP CD, choose boot from CD drive.. and it boots from the hard drive.. so I hook up an external CD drive, it works. windows installs then I log on, and it BSODs.. I try again with a different copy of XP. BSOD again.. Try it with 7, computer keeps rebooting at the welcome screen. So I try Ubuntu and it works. I install a video driver and then I get no video signal.. so I switch to onboard and it works! then it doesn't work.. for no apparent reason, the computer shuts off.. I tested the video card in my computer, and it worked fine. so I put back, hook the monitor back up to the card, and it works again >.< ok.. so Linux works now, but I want to get windows on that thing, I have tried swapping RAM, Power supply, Video card, unplugging everything except the hard drive and video.. no luck.. still BSODs. So without windows XP I can't flash the BIOS, at least not without doing it the old school way with a floppy and moving jumpers and stuff, and I don't have a floppy disk, or a drive in my other computer to make the boot disk with. I was told this computer was built by some friend of her brothers friend or something, and it's obvious he used the cheapest hardware he could find to build this piece of crap, every component in the system is some off brand.

Any suggestions?

If heat is still an issue, you could try lapping the heat sink and chip itself for a slight decrease in temp.

The bsod and reboots may be from a faulty motherboard, sure. Random shutoffs and slow performance are great indicators of this. Did you inspect the motherboard for leaky capacitors and/or anything unusual?

My 2nd pc is an ECS (Elitegroup) P4ITA motherboard. It has some leaky caps on it, but thus far, have not caused errors or performance issues. I'm waiting for it lol. In that pc, I already replaced caps and fixed the blown video card (6200 A-LE.)

Here's a decent read for anyone interested. It specifically mentions ECS:

http://www.epinions.com/content_3906576516

I took it out of the case and inspected it closely. No leaky caps or anything. I think the heat issue was mostly fixed when I applied arctic silver 5 and fixed the voltages. the weird thing is that no version of windows will run on it, I even tried reducing the clock speed and all that did was make it boot slower, it was no more stable than at stock speeds.

Did you get a chance to see what the BSOD stop error was? That would be a good place to start :)