Hmmmm, this is just a wild guess. I'm not even sure if this has to do something with it. It's just what I'd try to do in your case
1 - use fdisk (i have a win 98 bootdisk mysefl, it's the best tool ever..ghehe). Then type fdisk /MBR. This will clean up the master boot record.
2 - Try booting WinXP again after fdisk /MBR. If still not working, try making FAT32 partitions or NTFS, so windows will probably find the HD's. I'm sure fdisk does it, but I'm not very good with it, I use cfdisk, a more newbie (as me) version of it.
Again, I'm pretty dumb when it comes down to partitions and windows problems
. But give it a try if you've got nothing important to lose in your hd's
. Also sorry to give you so many "maybe, or perhaps, or possibly", but I really am not good at this problems, although, we all been there once too