I've just installed Ubuntu and the GRUB was put in the MBR (as recommended by the installation program). While beeting into Linux works fine, when I select Windows XP it just hangs.

The commands it has are:
root (hd0,0)
savedefault
makeactive
chainloader +1

When I do it manually in the command line, it all works fine until I run 'boot'.

Any help anyone can give me? Have I somehow screwed up my Windows installation?

-----
Northy

Here's entry to boot Win2K:
'rootnoverify' must be instead of simply 'root'. hd0 - first hard drive. The number after comma is the number of the partition which holds the windows loader. makeactive makes windows think it was booted from its partition and it's active. Try this.

Do a geometry (hd0) at grub prompt to check your partition table.

Boot into linux. Look in /etc/fstab and see which partition windows is on. hda1 or sda1 is drive 0, partition 0. hdb3 or sdb3 is drive 1 partition 2. I hope you can grasp the concept. Drives and partitions both start out at 0, but partitions start out at hda1 or sda1. There is no hda0 or sda0.

In /etc/fstab there should be a partition that is NTFS filesystem. Look at what it is.

In /boot/grub/menu.lst:

title windows
root (hd0,0)
chainloader +1

That is if windows is on drive 0, partition 0.

title windows
root (hd0,2)
chainloader +1

That is if windows is on drive 0, partition 2

It has caught my attention recently that in many XP installations a partion (could be hidden) may have been inadvertently set up by the user for the purpose of backing up XP system data or working as a swap. This partition may have been mistakedly picked up by Grub to boot as the XP.