How to remove GRUB using PartedMagic

Tony Littlejohn · 02-16-2010, 04:25 PM

I am having a problem removing RUB from my HD. I have deleted all the partitions using PartedMagic but still the message :

"Grub loading
error: no such disk
grub rescue>"

appears and I can get no further when attepmting to install any OS.

Any help in this matter would be more than appreciated so thanks in advance,

Tony LIttlejohn

tredegar · 02-16-2010, 04:35 PM

I suspect your BIOS is set to boot from your HDD first. So no other devices are seen.

Grub is still on the MBR of your HDD, but it has nothing to boot because you have deleted it all. So it cannot work.

Set your BIOS to boot from CD-ROM / DVD / USB or whatever you are trying to boot as first in the list of your BIOS.
Insert boot device (CD / DVD /USB).
Boot.
Follow the prompts.

OK now ?

syg00 · 02-16-2010, 05:20 PM

Or use the "Boot Menu" option if it shows on the Splash screen - e.g. Dell usually use F12 for this.
I have had equipment that ignore the BIOS boot order, and you needed to use a "magic" key during boot to get the CD to boot - hopefully doesn't happen these days.

pixellany · 02-16-2010, 05:39 PM

You typically cannot use a partition editor to remove grub, because GRUB is not in a partition.

CAUTION: DO NOT RUN THE COMMAND BELOW UNLESS YOU HAVE ALL YOUR DATA BACKED UP AND YOU ARE SURE WHICH DRIVE NEEDS GRUB REMOVED

Boot from any live CD version of Linux and run this command:
(I'm assuming that GRUB is on the first hard disk---modify as required)

dd if=/dev/zero of=/dev/sda bs=512 count=1

This removes the entire MBR. If you want to leave the partition table, then change the 512 to 446

Tony Littlejohn · 02-17-2010, 07:36 AM

Many thanks to all of you, particularly Pixelany, for your advice on dealing with my GRUB problem. I tried to use Cfdisk from within PartedMagic but was unsuccessful - no write permissions.

So, I moved onto a Knoppix Live CD, started Cfdisk and soon I had Mandriva 2010 installed.

Thanks again, my heart is beating more slowly now.

Tony Littlejohn