Hi, my XP OS would not boot up. It kept coming up with the message "system32\config\system file is missing or corrupted. Since I had a lot of valuable files on the hard drive, I didn't want to format and re-install XP. So I installed a second hard drive and installed XP on that. Now, the new OS will not access the old hard drive. It says that the file system is RAW and prompts me to format it. What can I do to restore my old hard drive so I can access my files? The new hard drive is using the NTFS file system. The old one contains FAT 16 according to some freeware that I downloaded that identified 99% of the volume as good. HELP!!!

What you might have done in the start is a repair reinstallation of Windows; this can be done with XP or Win98, either one. My first concern is actually why the old drive started giving you error messages, that is really the main problem.

Are you 100% positive that you installed XP on the NEW harddrive, and not mistakenly on the old one? It is very easy to do. Go into System/Administrative Tools/Computer Management/Disk Management, and see what is posted there for both of your drives.

Disconnect (just pull off the power cable) on your old harddrive, and try to boot into XP from the new one.
....* If it boots okay, power down, reconnect the old drive (make sure it is set to Slave with the jumper on the rear) reboot, and try to see the old drive in Explore;
....* If it will NOT boot into XP, reboot with your XP disk in the driver and perform a repair reinstallation (not a new installation!) which will reset your MBR to recognize the new drive as your boot path; remember that your old drive should still be disconnected at this point. When finished, power down, reconnect the old drive, and reboot. Now check in Explore and you should see the old drive, and hopefully you can access it to pull off the data you want. If the old drive is still unaccessable, or you get error messages, it may have mechanically failed. Try these steps and post back with the results.