XP dual boot - can't boot ubuntu anymore - all "howto" failed

[glasnhost]

Hi,

I had a working dual boot PC WindowsXP+Ubuntu.
When I reinstalled windows, ubuntu disappeared from the boot list.

I discovered that this is a well known problem and I tried the steps in
https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows
and its many variations.

However grub fails at the command "setup" with "error 12 invalid device requested":



ubuntu@ubuntu:~$ sudo mkdir /mnt/root
ubuntu@ubuntu:~$ sudo mount -t ext3 /dev/sda5 /mnt/root
ubuntu@ubuntu:~$ sudo mount -t proc none /mnt/root/proc
ubuntu@ubuntu:~$ sudo mount -o bind /dev /mnt/root/dev
ubuntu@ubuntu:~$ sudo chroot /mnt/root /bin/bash
root@ubuntu:/# sudo grub
sudo: unable to resolve host ubuntu
Probing devices to guess BIOS drives. This may take a long time.
root@ubuntu:/# sudo grub
grub> find /boot/grub/stage1
(hd0,5)
grub> root (hd0,5)
grub> setup (hd0)
Checking if "/boot/grub/stage1" exists... yes
Checking if "/boot/grub/stage2" exists... yes
Checking if "/boot/grub/e2fs_stage1_5" exists... yes
Running "embed /boot/grub/e2fs_stage1_5 (hd0)"... 17 sectors are embedded.
succeeded
Running "install /boot/grub/stage1 (hd0) (hd0)1+17 p (hd0,5)/boot/grub/stage2 /boot/grub/menu.lst"... failed

Error 12: Invalid device requested
grub>
I also tried grub-install:


ubuntu@ubuntu:~$ sudo mkdir /media/root
ubuntu@ubuntu:~$ sudo mount /dev/sda5 /media/root
ubuntu@ubuntu:~$ sudo grub-install --root-directory=/media/root /dev/sda
grub-probe: error: Cannot open `/boot/grub/device.map'
[: 494: =: unexpected operator
The file /media/root/boot/grub/stage1 not read correctly.My fdisk output is:
sudo fdisk -l
/dev/sda1 1 11 88326 de Dell Utility
/dev/sda2 * 12 8729 70027335 7 HPFS/NTFS
/dev/sda3 8730 14201 43953840 f W95 Ext'd (LBA)
/dev/sda4 13941 14201 2096451 dd Unknown
/dev/sda5 8730 13721 40098177 83 Linux
/dev/sda6 13722 13940 1759086 82 Linux swap / Solaris

I'll keep trying, if anybody has any suggestion, please let me know.
This problem is very annoying.

thanks

[jimmers]

Hi,
Are you installing Windows on a separate partition, or are you using the whole disk, if you are using the whole disk Windows will eradicate any other operating systems on the disk, entailing a complete fresh re-install of Ubuntu, use the partitioner to resize the hard disk to fit Ubuntu.


Hope this helps


Jimmers

[enli]

The easier method is to recover grub manually. (That is what I think and it always worked while explaining to my non-techy friends)

Open terminal from Live-CD and


sudo grub

This will give you a prompt like MS-DOS in windows, type

find /boot/grub/stage1
which will return something like (hd0,X). Note the number X.


root (hd0,X)
setup (hd0)

Replace X in above command. The last command should show 4-5 lines of messages and at the end something that says SUCCESSFUL. Reboot and you have your grub menu back.

[glasnhost]

Hi, thanks!

first, Windows was already installed in another partition of the same disk.
It seems that re-installing Windows only disabled grub bootloader, ubuntu is still there.

Any attempt to reinstall grub through the console, as suggesteed by enli, fails with
"Error 12 invalid device requested"
or "The file /media/root/boot/grub/stage1 not read correctly"
(see original post)

Las new is that I managed to reboot my existing Ubuntu partition with a SuperGrub usb-disk (http://www.supergrubdisk.org/w/index.php5?title=Main_Page) (http://www.supergrubdisk.org/w/index.php5?title=Main_Page).

However, I still need the usb disk to boot. I can't find how to restore permanently the grub bootloader.

g.

[presence1960]

Let's get a better look at your setup. Boot the Ubuntu Live CD. Choose "try ubuntu without any changes", when the desktop loads come back here and use the link in my signature to download the Boot Info Script 0.32 to the desktop. Once on desktop open a terminal and run this command
sudo bash ~/Desktop/boot_info_script*.sh This will create a RESULTS.txt file on the desktop. Paste the entire contents of that file back here. Once pasted highlight all text and click the # sign on the toolbar to place code tags around the text.

[glasnhost]

Thank you, very useful script.

However I've already found how to fix grub from the SuperGrub usb disk (http://www.supergrubdisk.org/w/index.php5?title=Howto_Fix_Grub#Quick_solution (http://ubuntuforums.org/Thank%20you,%20very%20useful%20script.%20%20Howeve r%20I%27ve%20already%20found%20how%20to%20fix%20gr ub%20from%20the%20SuperGrub%20usb%20disk%20%28http ://www.supergrubdisk.org/w/index.php5?title=Howto_Fix_Grub#Quick_solution%29% 20and%20now%20everything%20is%20fine))
and now everything is fine.

The script output doesn't show anything strange, probably because now GRUB is fixed...

thanks
g.