Problem with Boot up--C drive seen as RAW, not NTFS

Hi--

The system
I have a Compaq Presario SR2180NX with an Ausus P5LP-LE (Leonite) motherboard (here is the link to specs page: http://h10025.www1.hp.com/ewfrf/wc/...dest_page=documentIndex&product=3339276#N1406 ). It has a 2.8GHz Intel Pentium D chip, with 2GB RAM.

Also has a 250GB SATA drive as drive C:\ and a 1TB drive as drive D;\

All were working fine a week ago.

The problem

A week ago, I was trying to format a 1.5TB drive as an external USB drive for back-up, and having trouble getting it formatted. So, I opened up the desktop PC to swap out the D drive so I could format it directly.

When I put back the D drive, the problems began. At first the system would not boot and gave me the following message:

"Windows could not start because the following file is missing or corrupt
\Windows\system32\config\system

You can attempt to repair this file by starting Windows Setup using the original Setup CD-ROM.

Select 'r' at the first screen to start repair"

I checked the wiring, and then used Hiren's Boot CD ( http://www.hiren.info/pages/bootcd ) to check out the problem.

First, I tried to run XP Recovery, but the Recovery program "did not see any drives."

I then ran TestDisk 6.0--which saw the drives, but gave me the message "can't open file system. Filesystem seems damaged."

I then did a HDD regeneratorjust in case there might be damages to the drive, and found nothing.

I also then checked the MBR, and rebuilt it.

I checked the BIOS, and could see it.

I then ran a PE-Builder createed XP app, which loaded XP from the CD. That XP Windows system saw the C and D drives and their data. However, when I tried to run CheckDisk off that system, it said that both drives could not be checked because their format was RAW.

I am considering wiping the CMOS and rebuilding it as next step.

Any suggestions?

Thanks in advance for any assistance!