Linux – Repair Grub after install windows

grublinux

i got problem about my PC, my pc use dual OS, but after I install windows the grub cannot detect my BAcktrack,my Backtrack location in /dev/sdaa4, I try to repair but error :

sudo su
mkdir /media/bt
mount /dev/sda4 /media/bt

error
you must specify the filesystem type
next i try another command

mount -t ext4 /dev/sda4 /media/bt

error again

wrong fs type, bad option, bad superblock on /dev/sda4, missing codepage or helper program or other error

So what can i do for repair my grub?

Best Answer

The other answer is correct in the fact that Windows likes to think that it's the only OS on a PC.

What it really boils down to is popping your live CD back in, tell it to repair the Linux installation and that often does the trick.

In the future, I would always suggest the following order of events for setting up a multi-boot / OS PC:

  1. Linux LIVE CD Boot (pick a distro that you are comfortable with)
  2. Partition hard drive using the tools available on the live CD
  3. Install Windows on one of the designated partitions
  4. Install Linux (and / or other OS).