"BOOTMGR missing" or "Operating system not found" after Windows Server 2008, 2012 Bare Metal restore

SUMMARY

ISSUE

Purpose

This article addresses how to resolve a “BOOTMGR missing”error following a Bare Metal restore of a Windows 2008 server.

Applies To

Windows Server 2008

Symptoms / Description

When a system will not boot following a Bare Metal Restore

After completion of the BIOS post routines, the system remains at a blank console screen without attempting to boot from any internal hard drive.

After completion of the BIOS post routines, the boot procedure fails with a message similar to

BOOTMGR missing

Cause

In these cases, the probable cause of the boot failure is that the Windows bootmgr and Boot Configuration Database (BCD) were not restored during the Bare Metal restore. By default, the Windows installer places these components into a small partition separate from the partition that contains the Windows system. If the server contains multiple internal hard drives, then the Windows installer may place this partition on a disk different from the Windows system. Below is a configuration where this is the case:

BootMGR on disk 3

The Windows system partition C:\Windows is on disk 0 and the Windows BootMgr has been installed on disk 3 in a partition named System Reserved. The partition containing C:\Windows is not marked as Active and the System Reserved partition on disk 3 is marked Active. An Active partition is a bootable partition. Therefore, in this configuration, a Bare Metal backup will only back up the partition containing C:\Windows. The System Reserved partition containing the Windows BootMgr will not be backed-up since it is on a separate physical disk.

In a configuration where the Windows system partition and the BootMgr partition are on the same physical disk, a Bare Metal backup and restore will complete successfully, since both partitions will be backed up and restored together.

Resolution

The following procedure will allow the Windows BootMgr configuration to be recovered after a Bare Metal restore so that the server will boot properly.

Step 1: Boot the server using the Windows installation media.

Step 2: On the main screen, select Next and then Repair Your Computer.

Step 3: At this point, the repair procedure will not detect the desired Windows installation and will present none to select, even after storage drivers are loaded. Select Use recovery tools and then Next. On the following screen, select the Command Prompt option.

Step 4: From the command line, the first task is to make the Windows partition a bootable partition. Execute the diskpart.exe utility.

Step 5: While in the diskpart utility, list available disks.

DISKPART> list disk

Step 6: From the available disks, select the disk that contains the Windows installation.

DISKPART> select disk #

Step 7: List the partition, then select the Windows partition on the selected disk.
DISKPART > list partition

DISKPART > select partition #
User-added image

Step 8: Make the selected partition active (bootable)

DISKPART > active

Step 9: Exit diskpart utility

DISKPART> exit

The partition is now bootable. Reapply the master boot record and the boot sector. To do this, use the bootrec.exe utility:

bootrec.exe /FixMbr
bootrec.exe /FixBoot

When the master boot record and boot sector has been reapplied, rebuild the Boot Configuration Database (BCD) by executing:

bootrec.exe /rebuildbcd

The /rebuildbcd option will scan all disks for Windows installations. For each instance found, it will ask if that instance should be added to the BCD. Answer Y for the Windows installation that is currently being repaired.

When the Boot Configuration Database has been rebuilt, reboot again using the Windows installation media and select Repair Your Computer.

The desired Windows install should now be detected. If it is not, load the appropriate storage drivers. When the Windows install instance is displayed in the list, select it then click Next and choose Command Prompt. From the command line, execute:

X:\sources\recovery\StartRep.exe (Start Repair)

This will run for a few minutes looking for problems and attempting to perform a repair. Some of the repair activity will require a system restart to complete. Remove the installation media from the drive and allow the computer to reboot itself from the newly restored Windows install.