Grub2 detects Windows 7 when only Windows XP is installed

Do you have a \bootmgr or \boot\bcd file in your Windows filesystem? If so, what's in \boot\bcd?

Both files are present and c:/boot/bcd is a binary file.

I had a similar, maybe related problem:
I have installed three OSes in separate partitions in the following order:
Windows XP, Windows 7 Ubuntu 10.04.
Windows XP is on another hard disk as the other two.

My problem was that Ubuntu's Grub2 detected my Windows XP as "Windows 7" and could not boot it. (The real Windows 7 was detected correctly.)

I noticed that booting the Windows XP directly (by removing the Win7+Ubuntu HDD) worked, and presented a WinXP/Win7 selection dialog. What had happened was that the installation of Windows 7 had added the abovementioned \bootmgr file and the \Boot directory to Windows XP.

So my fix was to rename these items to bootmgr.bak and Boot.bak. Now grub-update correctly detected Windows XP and added "drivemap -s (hd0) ${root}" to its grub.cfg entry, which made it bootable and removed the Windows-internal superfluous WinXP/Win7 selection dialog.

Similar problem - triple boot system with

XP SP3
Ubuntu 12.10
W8 RP (build 8400)

Ubuntu and XP are on the boot drive, but when W8 was installed on its own drive, it overwrote grub and installed Windows Boot Manager in the XP partition. I restored Grub2, then switched the XP paritition from WBM back to NTLDR using

bootsect.exe /nt52 D: [from a W8 administrator System32\cmd.exe]

However, grub-update still recognizes the XP partition as Windows 8 (loader), resulting in 2 such entries in the boot menu. One runs XP, one runs W8, but you have to remember which is which.

It would be much cleaner if grub-update could read the volume/master boot code to figure out which is active, rather than "guessing" based on the presence (and contents) of bootmgr / ntldr files?