# Solved: GRUB Error 21



## nickeriss (Apr 3, 2008)

Hi
I had Windows XP and Ubuntu 8.04 installed on my machine
Now when I boot it says
GRUB Loading 1.5

GRUB error 21

or something along those lines

I had it set as a dual boot
I read that if I fix my MBR I can get it to boot into XP again
Can anyone tell me how to do this?


----------



## jrbuergel (Jan 17, 2004)

That grub error is; selected disk does not exist, and here is the actually Grub manual web site; http://www.gnu.org/software/grub/manual/grub.html#Troubleshooting . To fix your MBR, but not have the Grub, just boot to a real XP CD and press R for the Recovery Console, then at the text line prompt just type in this; fixmbr , and hit enter. This can also be fixed with some common rescue disks such as; http://ubcd4win.com/index.htm


----------

