Hi guys,

Few days ago my friend ask me to reinstall Windows on his computer. The problem is he has dual OS, ubuntu linux(Dapper Drake) and Windows XP. If I reinstall the Windows the Grub loader on MBR will overwritten by Windows XP. i know after reinstalling Windows we cannot boot to Ubuntu.

I'm newbie, So my question is, How we restore the Grub Loader back? I've try to boot from ubuntu using Live CD mode. But I still confuse the step-by-step how to restore the grub.

Please help



Thanks!

I'm not familiar with Ubuntu. I do this kind of things with Mandrake of Mandriva.
It should be the same kind of problem and the same solution on all distros, just try my way, it's not harmful as long as you do not clik "format the hard disk".
With Mandrake or Mandriva, and probably with Ubuntu, you boot on the first install CD (or on the install DVD), choose "install or update", then choose "update", it verifies a lot of things and you see "installing the bootloader". Choose to put the boot loader on your first disk, and everything should go fine.
Hope this helped.
Yordan

You Have Two Options............

1) The Usual Way....
After Installing WindowsXP, Boot a Linux Rescue Disk and Re-Install Grub with the command. "grub-install"

read man grub for more info.

typically....




2) The Easy, 733T haX0r Linux GuRu Way....

The Boot Sector is Stored on the first 512 Bytes of the physical Disk.

so... Backup your boot sector to a file like so...



Copy the backup file to a floppy disk / whatever.

Install Windows XP.

Boot a Linux Rescue Disk.

then Copy your Origonal Boot Sector Over whatever Garbage WindowsXP put there with the command





If at all in Doubt... Use Method 1..
If you Make a Mistake With Method 2, you can waye boodbye to your Partiton Table... File System, and look forward to a full re-partiton and re-format.

Good Luck.

Hi qwijibow,

I have tried the first method but it seems the parameter is wrong because when I run

$ grub-install --root-directory /boot /dev/hda

the grub-install just return same as we only typed $ grub-install. When run the grub shell, I saw a few command (I think) that can be used to fix grub. Like "setup" or "install",


I'm still confuse about INSTALL_DEVICE.



For method 2, I'll not do it because it's to danger and can make my partition table corrupt!. So, there is another way?

Thanks

GRUB handles each partition as a number... so if I want to install it into the the MBR, usually it would be:

grub-install hd(0,0)


xboxrulz

If you can boot from CD, simplest method is to mount linux partitions, then chroot to it, then run grub-install.
TIP: fdisk -l will display all partitions at all drives.

In general, for any distro, even you havn't live CD, restoring can be done in such steps:
1) Find any working linux sustem
2) Create GRUB boot floppy:
# cd /usr/share/grub/i386-pc
# dd if=stage1 of=/dev/fd0 bs=512 count=1
1+0 records in
1+0 records out
# dd if=stage2 of=/dev/fd0 bs=512 seek=1
153+1 records in
153+1 records out
3) Boot from that floppy, then (quote from GRUB info page):

Once started, GRUB will show the command-line interface (*note
Command-line interface:. First, set the GRUB's "root device"(1)
(*note Installing GRUB natively-Footnote-1: to the partition
containing the boot directory, like this:

grub> root (hd0,0)

If you are not sure which partition actually holds this directory,
use the command `find' (*note find:, like this:

grub> find /boot/grub/stage1

This will search for the file name `/boot/grub/stage1' and show the
devices which contain the file.

Once you've set the root device correctly, run the command `setup'
(*note setup::

grub> setup (hd0)


For more information type info grub

The RHEL installer provides the GRUB boot loader, GRUB (the GRand Unified Boot-loader).

/boot/grub/grub/grub.conf has a format of global options followed by boot stanzas. Here is a sample grub.conf:


timeout=5
splashimage=(hd0,0) /grub/splash.xpm.gz
password --md5 $1$/iX9y$Bkskfdsd4443gnff
default=0
title Red Hat Enterprise Linux AS (2.6.9-648_EL)
root(hd0,1)
kernel /vmlinuz-2.6.9.EL ro root=/dev/VolGroup00/LogVol00

initrd /initrd-2.6.9-648.EL.img
title Windows XP Pro
rootnoverify (hd0,0)
chainloader +1


IF ggrub-install fails for some reason try the following:

1. type the command grub and press enter

2. type root (hd0,0)

3. type setup (hd0)

4. type quit



IF still problem occures, then reinstall the grub by

/sbin/grub-install /dev/hda or use these three commands:

Have a nice day

root(hd0,0) means partition where kernel is stored w.m. where /boot/ directory is stored
hd0 = first IDE disk, 0 means first partition on this disk - you can use tab key to show alternatives

setup(hd0) means where to install grub to MBR, on which disk - so in this case in the MBR on the first IDE disk

Restoring Red Hat Enterprise Linux Boot Loader
Restoring Grub Boot Loader

Hi

I had dual boot system of windows xp and RHEL 3.0.After some days I have reinstalled XP.But now I want to get back RHEL 3.0 again.

How Can I restore Grub boot loader again?if I can restore the grub boot loader again,will it give me the option of selecting the operating system?

Please help me out...

-question by ruhul

Dual Boot - Solaris 10 and Windows XP
Restoring Grub Boot Loader

Hi,
I installed solaris 10 first.Then I install windows xp in another partition.When I boot my system,there is no options for os choices.It directly goes to the windows xp ,how to get os choices menu.

Thanks in Advance.

By,
Ruban demel.

-reply by Ruban