GRUB failure after WinXP re-install

[Jim Cornette]

On 07/18/2004 06:05:33 AM, Mikael Konttinen wrote:
> 
> All,
> 
> I've finally got a working Windows XP again and no data loss on the
> NTFS
> data partitions, though it was done with a fresh re-install of  
> Windows
> XP.
> During the installation of XP apparently the MBR was rewritten again,
> this
> time with the result that GRUB no longer works. Somebody mentioned
> that
> possibility earlier, though I didn't listen as I thought that since
> GRUB is
> written on the /boot partition and not on the MBR, it shouldn't be
> affected.
> Also, from what I've read (or the way I got it), Linux doesn't give a
> fork
> about the given CHS/LBA disk geometry and therefor shouldn't be as
> vulnerable to inconsistency as WinXP apparently is.
> 
> Anyway.
> 
> What happens when I try to boot GRUB is that GRUB loads but halts  
> with
> its
> command prompt. No menu anymore, though all kernel and conf files  
> seem
> to be
> in place when I mount the /boot partition from a linux CD boot. I
> recalled
> the rows from the grub.conf and manually typed root(hd0,0)  
> chainloader
> +1
> and boot to get back into Windows XP again so it seems like GRUB is
> working
> although it doesn't find the confs for some reason.
> 
> I've googled for this strange problem, but all results I find on the
> topic
> is about getting XP booting. Didn't find anything appropriate in the
> Bugzilla or FAQ and the man page didn't give me any clues neither.
> 
> 
> Yours
> Mkn.
> 
> 
> PS. I got infected with the non booting WinXP after installing Fedora
> Core 2
> and the published LBA/sfdisk fix didn't work. Got a bit nervous there
> as
> I've got OS and NTFS data partitions on the same disk and really
> really
> really didn't want to loose the ~80-100 gigs of raw video and audio
> work as
> the result of a defect partition table. ... Yes, mom. Time to learn
> about
> back up routines. ;)

It's great that you didn't lose your AV data.

About grub after the reinstallation of XP. I had a similar symptom when  
upgrading systems before. I ended up booting from the first CD in  
rescue mode.
linux rescue
After getting into rescue mode, I typed the below to change the  
environment to the FC install.
chroot /mnt/sysimage
This gave me a shell with a bash prompt still, but the programs from FC  
worked fine.
Now, I would rerun grub-install. This depends on where your boot  
partition is located snd on which partition is active for boot. In my  
case /dev/hda1. I believe that you have /dev/hda2 setup as active and  
as your boot partition.
grub-install /dev/hda2
This works for me with several FC installations on the same machine.  
Why it sometimes corrupts with reinstallations of one OS or another is  
beyond me.

Good luck and hopefully this works for you. Backing up data is still  
wise to do though.

Jim

-- 
A quarrel is quickly settled when deserted by one party; there is no  
battle unless there be two.  -- Seneca