Repair the Master Boot Record

From ReactOS Wiki
Jump to: navigation, search

This tutorial intends to show you the steps to repair the master boot record using Super Grub Disk to be able to start FreeLoader. Super Grub Disk is useful to recover GRUB after having installed Windows too.

The Problem

The story starts like this: I wanted to install ReactOS on a hard drive where I had X/K/Ubuntu or your-favorite-distribution, and I had to install LILO or GRUB, I deleted all the partitions, I have made a new one for ReactOS and I suppose the disk is clean, now that I have installed ReactOS I can't start FreeLoader.

00-grldrfreeloadergrub.jpg

Due to #2733, ReactOS cannot boot with a boot loader previously installed on the disk.

The Solution

You will first need to ensure your computer is set to boot from the CD drive before the hard drive. This is done by changing the boot sequence in the BIOS settings (refer to your computer manual for information on how to access the BIOS settings). In some motherboards, to start the computer from a CD or DVD, you hit F8 or F11 to enter the menu where you choose where to boot from.

Download Super Grub Disk and burn it to a CD or DVD (rewritable preferably) using any software of your choice. Start the computer with the CD in the drive and boot from it. Choose the following items to repair the master boot record:

  1. Super Grub Disk
  2. Choose Language & Help
  3. English Super Grub Disk
  4. Windows
  5. Fix Boot of Windows (Fix Windows MBR)
  6. Syslinux
  7. Select the hard disk
  8. Super Grub Disk will complete the request and show SGD has succeeded
  9. Reboot P.C.
  10. Remove the CD from the tray and boot from the hard disk.

After this, the master boot record will be ready to proceed with the installation of ReactOS without issues.

Using DOS

Typing "FDISK /mbr" will rewrite the MBR on your hard drive; typing "SYS C:" will copy boot files to the C: drive. source

Using Windows XP

  • Boot to the Recovery Console
  • type "Fixboot c:"
  • type "FixMBR"

Using Windows Vista/7

(Need tutorial on using BCDEdit)

ReactOS crash and makeactive of GRUB1

Loading of ReactOS through GRUB1 (so-called "legacy GRUB") with makeactive flag set, can bring, in case of errors with ReactOS loading to misplaced active partition error: i.e. the active flag set to worng partition, tranforming the formerly working system into inusable one. To correct this, one may use the (GPL) fixparts utility

Commands of interest are 'a' and 'p'

External links