You problem, I assume, is that windows was not installed on the very first partition of the HD.
There should be three primary partitions, and an (optional) extended partition with as many additional FAT32 drives as you see fit.
WinXP will install to the first one - it don't matter whether it is NTFS of FAT32.
The second primary should be a tiny swap partition with the boot loader. How the motherboard BIOS knows to check the boot-loader before booting windows is beyond me, but it works.
(I am still a newbie, but RedHat set this one up very easily, thanks in part to the fact that my 40 Gig HD was already split into C: / D: - 8/30 gigs, however, cramming all my docs & programs off the D drive and onto C, and deleting entirely the D drive (about 85% of my Windows programs) really made windows ME very screwy, but it still booted...)
The third should be the Ext3 partition that installs Linux OS...
The fourth (optional) extended partition can be a smaller FAT32 that can be accessed by both operating systems.
Windows is far pickier that Linux about where it is installed, and if it was further down the drive than Linux, and you deleted the Linux partitions, then the BIOS would look to the boot sector of the HD and find nothing - I am assuming that after you installed the Windows XP again on FAT32, then the OS logically assigns all drive letters in the logical order they appear: C, D, E, F, G, and so on.
D, E, and F are probably all of the ghosts left over from Linux that WinXP cannot interpret, and you are indeed very lucky that you can still access your precious data after Partition Magic F***ed up your HD. You may probably now have split, fragmented partitions, and all sorts of garbage!
Disks were originally designed to be partitioned and then formatted, and then have dataplaced on those formatted spaces.
They were NEVER originally intended to have partitions, etc, moved around and reformatted while simultaneously preserving the data intact.
These softwares work by hacking the drive structure in ways it wasn't intended.
So my advice to you, is backup your precious data before anything gets further messed up, with whatever means you have available, CDRs, USB-flash drives, ZIP disks, of even FLOPPIES, heaven forbid!!!
You need to COMPLETELY DELETE ANY AND ALL PARTITIONS off the drive, then reboot, repartition, or better yet, trash partition magic, then use a spare HD if it is good with no bad sectors, and Install XP on the bigger one, Linux on the other, screw the whole entire boot-loader idea, and use your motherboard BIOS to pick which drive to boot (usually in the form of a menu) when you power up the computer - Put them both on the same ribbon cable - One should be set to "MAster" and the other to "SLAve"
Then you can use a simple USB 2.0 flash drive (FAT-formatted) to transferre all of your files back and forth tween Windows and Linux. And get a BIG one, like a 1.0 Gb SanDisk or something. If one OS gets shot and goes to hell, the other will not be affected at all. What's more, you don't have to configure anything else at all