A routine update wrote Grub in the MBR; how do I undo it?

Question

I have Ubuntu 12.04 and Windows7 installed onto a machine so that I could boot into either one. I wanted to keep using the Windows bootloader (actually EasyBCD), so I made sure that I didn't install Grub into the MBR, and all was well.

However, a week or two ago, just doing a routine update with Update Manager, it updated Grub but put it into the MBR (without telling me and without asking my permission), disabling the Windows bootloader, so now the machine boots into Grub instead. I'd like to get it back to booting into the Windows bootloader.

I've read it is easy to fix this, but I don't know how. Any help?

Answered here: http://askubuntu.com/a/150644/68508 – BigSack Jun 14 '12 at 05:04 — BigSack, Jun 14 '12 at 05:04

score 3 · Accepted Answer · answered Jun 14 '12 at 01:52

3

Go to the "BCD Deployment" menu in EasyBCD. Then click the "Write MBR" button.

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Reboot, and you're all set!

answered Jun 14 '12 at 01:52

Emerson Hsieh

6,900

score 2 · Answer 2 · answered Jun 13 '12 at 14:45

2

To reinstall the Windows boot loader you will need to boot the windows recovery console ( possibly via the install cd ) and run the FIXMBR command.

To make sure grub isn't (re)installed to the MBR, you need to run sudo dpkg-reconfigure grub-pc and make sure it is not configured to install to the whole drive ( /dev/sda ).

answered Jun 13 '12 at 14:45

psusi

37,551

Ick! That isn't so easy. This is on my mother-in-law's computer, and the computer came with Windows7 pre-installed - of course - so I don't think she has any install CD. – Kelley Jun 13 '12 at 14:58
@Kelley, you may still be able to install the old lilo package and use lilo -M to install a dos compatible MBR. – psusi Jun 13 '12 at 15:48

score 2 · Answer 3 · answered Jun 14 '12 at 01:49

Both answers were great so I upvoted them. In the end, I found it easier than I might have imagined.

Since I had used EasyBCD on Windows to set up the Windows boot manager, I opened it and found an option to repair the MBR. I ran it - somewhat nervously - rebooted, and it was all back to normal! Nice program!

A routine update wrote Grub in the MBR; how do I undo it?

3 Answers3