WinXP32 Boot problem. NEED HELP

Hi all, heres a challenge for you.
I hope someone out there can help me as this is driving me slightly mad.

A few days ago I was loading 3 application at the same time just after booting up. Hard drive was hard at work and I accidently cut the power to the computer. I didn't think anything of it and just went to reboot. I got down to the menu with safe mode, safemode with newtwork support etc. etc. But no matter which option I tried and I tried them all many times. The same thing happened. It would carry on booting for a second or two then reboot and go back to the same menu.
I figured that one of the crititcal files in windows had been corrupted. So I backed up my data, stripped my system to bits and reformatted and started again. When it happened I was running two hard drives in a raid 0 on for my C: drive.
My system is as follows:
AMD Athlon X2 4200+
Asus A8N32-SLI Deluxe
2x 1GB OCZ Platium DDR PC3200
XFX Nvidia Geforce 7800 GT 256mb
Creative X-Fi Elite Pro
2x 250GB Hitachi Deskstar sata2 T7K250 - were in raid 0 as C:
2x 500GB Seagate baracuda 7200 sata2
Seasonic S12 Powersupply 600W
Antec P180 case
1 DVD Rom Drive
1 DVD Rewrite drive
120GB IDE drive
160GB IDE drive

I took out the sound card, 2 IDE hard drives, 1 of the 250GB hard drives and both of the 500GB hard drives.
Fortmatted the system, reinstalled everything, and updated it all. put back the sound card and the two 500GB hard drives.
But now I'm getting the same problem again. However if I remove one of the 500GB hard drives while it boots, it does so without a problem, but won't boot if I have them both in there during the boot. Doesn't matter which one I remove. I can then add it back in once the systsem has booted into windows.
I'm no longer running the system with a raid. But don't know whats causing this problem to occur.
I'm Running WinXP32 SP3 - legit. All software is legit etc.

Really need help
Many thanks
CC

No Just 1 OS. Just have lots of files I store. I do video editing and so keep one of my 500GB gard drives jsut for editting on etc. But the rest are full of well stuff.