I am running Debian, Ubuntu, Mint10, Mint12 and just installed Mandriva. Mandriva took over grub. I had to re-install Debian to get the full grub menu, but now I can't get into Mandriva.

Everything I have been reading says I need to edit the MBR, but (always a but) I don't know how to get into the MBR to edit it?

How do I do that?

Help ....Please

You don't. MBR is the master boot record i.e. the first 512 bytes of your hard disk. Here resides code to start the boot loader (and the partition table of the primary and extended partitions), which means the place where to find GRUB is "hardwired". Thus the problems with your installations.

In short: leave the MBR alone, it only chooses which installation of GRUB to use and (presumably) they all work.

When you want to change the boot menu you have to change (edit) /boot/grub/menu.lst of your "ruling" GRUB.

For more information and how to do that read first:

http://en.wikipedia.org/wiki/Master_boot_record

and then e.g:

http://www.dedoimedo.com/computers/grub.html
http://www.troubleshooters.com/linux/grub/grub.htm
http://www.linuxselfhelp.com/gnu/gru...er/grub_1.html
http://www.gnu.org/software/grub/manual/
http://www.justlinux.com/forum/showthread.php?t=147959
http://www.linuxquestions.org/questi...hooter-237511/
http://www.linuxquestions.org/questi...7/#post4159819

You don't edit the MBR directly.

You are mixing systems that use different boot loaders. Each install you do, if you let it, will install its boot loader, and it will install where you tell it. The usual place is the MBR.

Mandriva uses Grub1, The buntus use Grub2. I have never used Debain, so I don't know what boot loader it uses by default.

It sounds like from what you posted, Debain uses Grub1 ? is that correct?

If that is correct, in Deb go in and edit grub; the file will be /boot/grub/menu.lst and put an entry in for Mandy. If you get the entry correct, Mandy should boot. There are How To's around for editing Grub. Look for one of them if you need help.

I have Magia 1 installed, I got away from running Mandriva after many years of use. I now use Slackware as my main system. I boot it with grub installed with Magia.

Indeed. I overlooked Ubuntu, which uses GRUB2. You can either chainload that or load the /boot/core.img. This is probably bewildering, start slowly with one step after another. This is a short tutorial on GRUB2:

http://www.dedoimedo.com/computers/grub-2.html

Not a good idea to highjack a foreign thread marked as solved (with a redundant copied post)...

@frank75riz Solved how? It would be nice if you gave a short explanation for other interested readers to see a solution which worked for you.

I doubt that this is a GRUB problem, since you can't even mount the partition housing presumably your /boot directory. So, fire up Knoppix and run "fsck". For more information and options (if needed) "man fsck".