Triple boot setup (Linux, Win7, WinXP); XP reports NTLDR missing

After considerable tinkering I've managed to properly partition and install three operating systems in my netbook - Linux Mint Debian Edition, which I use normally; Windows 7, which I use when I need some Windows-specific application that is unavailable in Linux; and Windows XP, which I use (disconnected from the Internet) to interface with some old hardware that has no drivers available for 7 and won't work properly in virtualization.

The last round of tinkering resulted in me finally configuring grub2 properly, so I can now select and boot all three partitions. However, while LMDE and 7 run fine, trying to boot XP results in a "NTLDR is missing" error.

How do I fix this while leaving the rest of the boot procedure untouched? I've tried Googling and applied the found solutions, but they all rewrite the MBR. I can then easily restore grub2, but I lose the ability to boot 7. And if I then restore boot ability to 7 (from the install disc) and re-restore grub2, I again lose XP.

This is a Windows forum. We pioneered many of the fixes for Win7, which may not apply here since you are asking about GRUB.

In a typical XP-Win7 Dual boot where Win7 is installed second the Win7 installer only updates the boot files on XP to boot Win7. Then to add Linux what works best is here: Dual boot Ubuntu-Win7

Normally to re-establish a failed Windows boot menu what works best is to Mark Win7 Partition Active then run Startup Repair - Run 3 Separate Times. This moves the System flag and boot files to Win7 or its' System Reserved partition so the more modern OS is booting the system, and the multi-faceted repair checks and fixes many other parameters.

You can then install EasyBCD to add XP to a Dual Boot. EasyBCD (click Download - no Name or Email required)

However since you're relying on GRUB it may require a Linux solution and not Windows, unless you want to add the Linux distro per Dual boot Ubuntu-Win7.

Another method is here to Dual Boot - Windows 7 and Linux - Windows 7 Forums whose author may be able to help you better if contacted through the comments section.

My system
AMD64
4GB RAM
3 SATA hard drives

My system hard drives and partitioning:
SCSI3 sda 82.0GB Windows XP
#1 primary 81.9GB Bootable ntfs
SCSI4 sdb 82.3GB Windows 7
#1 primary 82.3GB ntfs
SCSI5 sdc 160.0GB Debian 7.7.0
#1 primary 10.0GB ext4 /
#5 logical 6.0GB swap swap
#6 logical 144.0GB ext4 /home

Installation process:
1.- Install Win XP first
2.- then install Win 7. Select the [EMS enabled] booting option at the beginning of the installation
3.- finally install GNU/Linux. When asked for the installation of GRUB in the MBR (Master Boot Record) say yes.

Performance:
During booting Grub will ask for Debian 7.7.0 Wheezy or for Windows 7 (NO Windows XP option is shown), if you select the WinDogs option, the Windows bootloader will be charged and will let you choose between Win 7 or Win XP

Enjoy with GNU/Linux!
... or suffer with the other guys...

This is a bit of a necropost, but just in case someone stumbles upon this and has the same problem, I found a bunch of boot files in the root of the Win7 install that looked more old-school than I expected (autoexec.bat and such). I moved them over to the XP partition's root directory and that caused XP to boot again.