The bottom line is my computer wont stay on for more then 1-2 seconds after I push the power button. The lights will blink and the fans will start then after about a second everything turns off. I've tried flashing the CMOS and removing items which my be putting a strain on my power supply, but nothing helps.

Here's all I know. As of yesterday my computer was working fine and I set up some downloads to run throughout the evening and then went out for the night and left the computer running. I came back home around 4-5 this morning and saw that everything was still running fine and that the downloads were almost complete. I set the FTP program to disconnect from the internet and shut down the computer when the downloads were completed and then I went up to bed. I got up this morning around 10 and found that the downloads had completed (or so I assume) and the computer was no longer connected to the internet. However the computer was on and the screen showed my desktop as though the computer had just been started, my icons were on the side and the mouse pointer was in the center of the screen. I went to shut down the computer but the mouse pointer wouldn't move, so I held down the power button until the computer turned off. I then tried to turn the computer back on however my computer would hang at the first sign of loading the OS (Win2k). Over and over again I would restart the computer and it would go to the first screen where it looks like it's loading the OS and then it would freeze. I assumed it might be something with OC'ing my CPU so restarted my computer and went to the BIOS and lowered my CPU speed (however I did leave the voltage at the higher setting). When I told the system to save my changes and exit it immediately shutdown and did not restart. Ever since then if I turn on my computer the lights will blink and the fans will whirl for a second then everything will suddenly turn off, the monitor doesn't even have a chance to turn on. Like I said I flashed my CMOS, I also unplugged some ROMs and removed an unused PCI card to reduce the load on my PS, all to no avail.

Other things to point out, I had updated my virus protection earlier in the day so it was definitely up to date, and it was actively monitoring my system. I have my virus scanner set to activily scan and immediately quarantine any infect files, so it's unlikely (in my mind at least) that I may have downloaded a virus. Also, the download was from a very professional/respectable company so that (to a degree) helps rule out the chance of downloading a virus.
I also had a firewall running during my download, I know it's excessive to have a firewall on a dial-up connection but I almost always have ZoneAlarm running when I'm connected to the internet. So the fact that I'm on a dial-up connection with a firewall running helps rule out the chance of anyone pinging my system and planting any virus or trojans.

Anyone know what I should do to try to get my system running again? I'm not too worried about loss of data because most of my system was backed up a little while back. However I'd really like to have the files I've downloaded over the past 2-3 days (and I don't want to have to re-download 300+ MB on a dialup). Any help, tips, tricks, or guidance you guys could give me on the matter would be greatly appreciated

The basics of the system:
Abit KT7-RAID
AMD T-bird 800MHz OC'd
256MB of RAM (I've had this RAM for almost a year now and it's from crucial.com so I don't believe my RAM suddenly went bad or anything.
2x 30gig HDs in RAID-0 formation…one of the HDs is an IBM 75GXP and some people have had problems with theirs however I've never had a problem with mine and I seriously doubt it is causing the problem. The other HD is a Maxtor DiamondMax Plus

Thanks for your help, sicko