# "bootmgr is missing" Error



## mangatrekkie (Feb 22, 2012)

I wiped my hard drive several months ago and tried to install Windows XP Pro OEM (Someone gave me this computer and I wanted a fresh start.) This didn't work, so I formatted the hard drive using external enclosure kit. I got a weird error message when reinstalling, so I left it for several months and haven't really touched it. Now I am trying to install Ubuntu 11.10 and after it starts up and gets past the POST, I get message "bootmgr is missing press ctrl+alt+delete to restart" I recently took out graphics card and put it back in for practice, but I'm sure I put it back in correctly. I installed two computers using the same Ubuntu disc like two days ago. I have used multiple disc drives to boot from CD. No USB drives are attached, so its not trying to boot from those. How do I install Ubuntu using the CD?


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## arochester (Jan 17, 2007)

Have you checked the BIOS to make sure that it will boot from the CD-Rom first, before the Hard Drive?

If the disk clean?


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## saikee (Jun 11, 2004)

bootmgr is the boot loader for Vista and Win7.

The hard disk partitions might have been removed but the MBR still has the old boot loader which is not broken.

If Xp is installed then its boot loader NTLDR will automatically overwrite the bootmgr.

The error message could be forcibly removed by writing the MBR by booting Ubuntu, or any Linux, and run it as a Live CD, click a terminal and issue this command at the terminal

```
sudo dd if=/dev/sda of=/dev/null bs=1 count=1
```
where device sda is the hard disk. The above command will zero the first sector (512 bytes) of the hard disk and should only be done when there is nothing in hard disk. Formatting as a rule never touches the MBR.

In a normal installation of a Linux or Ubuntu there is no need to do the above as Linux's boot loader, usually Grub, will overwrite the MBR.

To get rid of a boot loader one must overwrite it with another boot loader.

--------------------------------------------A demonstration of MBR being outside a partition-----------------------------------------------
Here is the geometry layout of my hard disk's first 10 partitions. The unit displayed is in sector

```
Disk /dev/sda: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x73696d20

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *          [COLOR="Red"]63[/COLOR]   112471064    56235501    c  W95 FAT32 (LBA)
/dev/sda2       112471065   337413194   112471065   1c  Hidden W95 FAT32 (LBA)
/dev/sda3       337413195  2930272064  1296429435    5  Extended
/dev/sda4      2930272065  3907024064   488376000   83  Linux
/dev/sda5       337413258   340642259     1614501   82  Linux swap / Solaris
/dev/sda6       340642323   453113324    56235501    7  HPFS/NTFS
/dev/sda7       453113388   565584389    56235501    7  HPFS/NTFS
/dev/sda8       565584453   678055454    56235501    7  HPFS/NTFS
/dev/sda9       678055518   790526519    56235501    7  HPFS/NTFS
/dev/sda10      790526583   902997584    56235501    7  HPFS/NTFS
```
As one can see the beginning of the first partition sda1 does not start from 0 or 1 but 63th sector. The first track, 63 sectors x 512 bytes = 32256 bytes, of a hard disk is never used in any filing system but reserved for the boot loader. Thus formatting a hard disk, which is removing or changing the partitions or the zeroing a filing system inside a partition, has no influence on what has been stored inside the first track.


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## mangatrekkie (Feb 22, 2012)

Arochester, yes I have made the CD boot in the first order. And Saikee, I cannot go into a terminal as the computer won't boot to the CD. Is there a way to overwrite the MBR without being able to boot to a CD or OS?


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## arochester (Jan 17, 2007)

The CD itself should write Grub2 to the MBR. The message "bootmgr is missing..." should not appear because it is on the Hard Drive and the computer should be booting from the CD-Rom.

It "should" be very straight-forward. Put the CD in. Reboot the computer.

If this is not working *I* would check the leads to the CD-Rom and make sure that they are correctly seated.


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## saikee (Jun 11, 2004)

If you install a MS Windows then you will need the CD/DVD working working.

One can use a Grub1 stored in a floppy to overwrite the MBR but that means the MBR has Grub1 instead of bootmgr.


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## mangatrekkie (Feb 22, 2012)

So what you are saying is that I should create a new CD?


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