Here is the situation...

I had Red Hat 9 on 80GB drive and winXP on 160GB(NTFS) drive. GRUB started on boot-up and asked me which I wanted to load. I didn't really use Linux very much, just installed it to play with it and learn. All fine and dandy.

I wanted to use the 80 GB drive for another computer, with winXP on it, so I unplugged the 160GB drive, plopped in the winXP disk and formatted and installed XP on the 80GB. Everything is ok so far.

I switch back to the 160GB and it won't boot XP, as expected. I stuck the XP CD in and ran fixboot and fixMBR which I thought would do the job. No such luck. Booting it gives "NTLDR is missing. Press any key to restart"

I then hooked up both drives and booted the 80GB one. I ran partition magic 8 and on the 160GB it shows first a 500MB linux swap (status=none, primary partition), then the rest (152,123 MB) is a FAT partition!? (status=active, primary partition) It also gives me errors saying "FAT copies are not identical" and "cross-linked files were found".

'My Computer' shows it as a 10MB FAT drive.

If I erase the linux swap partition will it boot? I'm almost afraid to touch it now. I REALLY don't want to loose the data on it.

Does anyone have any ideas on what GRUB changed on my 160 GB drive and how to fix it so it is bootable, or at least readable?

So are you saying you want to trash linux off of your system? Then delete the swap partition. If your hard drive is something like this order:

linux swap(82), NTFS, ext#/reiserFS

then delete the linux swap, then figure out how to MERGE your empty space with your NTFS(If you can't go directly, then format the empty space as NTFS through PM, and then merge) You won't lose any data from your existing space, it'll just fill up the beginning of the new, bigger partition. After that, I'd reformat the second partition as ntfs and use it as a backup for files you make through Windows(Documents, etc). I'd also defragment. After all of that, I'd split up your first 80GB partition up into 3 or 4 partitions so that way the formatting doesn't eat up about 5-10GB of your available space.

Correct. Linux is no longer on the system. Whatever GRUB did to my XP bootloader is what I'm trying to reverse.

I just now erased the Linux swap partition, and left it as unallocated space, but booting still gives me the NTLDR missing error. I guess that is my main question. How do you fix this error?

Boot from Windows XP CD and try to choose repair windows when menu comes, I think it will solve the problem of missing NTLDR.

Make sure that you overwrote Grub's entry in the mbr.

Wow, I didn't realize I was member. Anyway, there are actually two things you need to do here. First, either boot off of a live linux disk or DOS boot floppy. run fdisk to make sure that your XP partition is the bootable partition (Doing this won't delete data because you are not repartitioning). After you change the bootable partition reboot and boot to your Windows XP install CD. When prompted choose repair, this will start the repair console. It should ask you which windows installation you want to repair. If you've only got one, only one will be listed. Select the one you want to fix and then you will be prompted for the administrator password. Once you enter that you will dropped to a dos prompt. Type: fixmbr It will then ask you (Like ever other MS product in the world) are you sure? Obviously say yes and it will restore your working MBR. Have fun.