PC /WinXP RESTARTS after attach RAID1 HDD

Hello Tom's HW and all Members,

I have a PC with the following spec:
- MSI7021-KT6V mainboard
- AMD Athlon XP 1.7
- 1Gb RAM
- 2 SATA ports
- Maxtor 250Gb SATA2 as boot hdd
- MS Windows XP Pro O/S

I have NAS device (2 bays, SATA), using WD 500GB @ RAID1. Recently, the 2nd bay hdd is not working.
So I can't access the NAS Control Panel (C/P). I had to remove the 2nd bay HDD and then only can access NAS C/P. However incidently, the 1st bay hdd data lost.

Therefore, I take out the 1st bay hdd and attached directly to my PC. However - my problem is - after installing the hdd, my PC keeps on restarting by itself. Once the WinXP logo appears, it's fading and then restarts the machine. Urrghh!! Really makes me crazy and turn upside down!!! I just unable to find out why it was happening like that! For your guys info, I'm using WD 500Gb SATA2 hdd for NAS.

Hope you guys can help me to sort out this matter quickly because my client is waiting for my work very very URGENTLY!! It's very unfortunate the NAS Storage became that way!

I understand that if 2nd bay hdd failed, the 1st bay hdd should be able to be read as usual after taking out the 2nd hdd. This really annoying me and I just can't find solution immediately now. I need to access the hdd so that I can do Data Recovery to get the mising files.....

Is it because of my mainboard? I've already update the BIOS after trying to attach the NAS hdd, but still facing the same problem.

PLEASE HELP ME... really appreciate you guys!!!

Hit f8 and stop boot on error.
Let us know what the error is when it comes up.
You may need to do a repair install of windows on that disk.