Which operating system was installed last? The NTLDR seems to change with each major OS release. I would get your XP disk, boot with it and choose Repair. I have Win98/2K Pro/XP Pro on my machine and I really had to monkey with the boot.ini to get all of them to boot properly. 2K and XP see the partitions in different orders for some reason and assign different drive letters once the OS has booted up.
How many hard drives do you have? If more than one, change the rdisk(x) number around and see if that helps. If just one hard drive, keep playing with the partition number. Or repair it with the XP disk like I said above.
How many hard drives do you have? If more than one, change the rdisk(x) number around and see if that helps. If just one hard drive, keep playing with the partition number. Or repair it with the XP disk like I said above.