How To Rebuild System Reserved Partition From Scratch

System reserved partition is a small (100 MB) non-NTFS partition containing Windows Boot Loader and its configuration (BCD registry hive). Usually there is no drive letter assigned in Windows for system reserved partition, albeit this partition is mounted, accessible via volume-GUID path, and its BCD hive is usually mounted at HKEY_LOCAL_MACHINE\BCD00000000.

Windows will not boot without system reserved partition.

This article is for people who accidentally deleted or formatted system reserved partition and need to rebuild system reserved partition from scratch without reinstalling Windows.

Contents

1. Solution in a nutshell

  1. Boot into Emergency Boot Kit.
  2. If 100 MB system reserved partition does not exist, create it with Emergency Boot Kit Partition Manager.
  3. Format system reserved partition with Emergency Boot Kit Partition Manager to VFAT filesystem.
  4. Using Emergency Boot Kit File Manager: copy \Boot folder from your Windows installation DVD to the system reserved partition; also copy BOOTMGR file to the root directory of the system reserved partition.
  5. Delete BCD hive (\Boot\BCD) from system reserved partition using Emergency Boot Kit File Manager.
  6. Run Emergency Boot Kit Mount & Boot Center to recreate BCD hive from scratch.

2. Step by step guide

1) Download Emergency Boot Kit and deploy it to USB thumbdrive according to the instructions, then set up your BIOS to boot from USB thumbdrive.

2) Boot into Emergency Boot Kit and run Partition Manager from the main menu:

Rebuild System Reserved Partition From Scratch - Run Emergency Boot Kit Partition Manager
Rebuild System Reserved Partition From Scratch - Run Emergency Boot Kit Partition Manager

3) Assuming system reserved partition does not exist, create it (otherwise, format it):

Rebuild System Reserved Partition From Scratch - Create new system partition
Rebuild System Reserved Partition From Scratch - Create new system partition

4) Set its size to 100 megabytes:

Rebuild System Reserved Partition From Scratch - Set size of new system partition
Rebuild System Reserved Partition From Scratch - Set size of new system partition

5) Set its filesystem type to VFAT and volume label to empty:

Rebuild System Reserved Partition From Scratch - Set filesystem type and volume label of new system partition
Rebuild System Reserved Partition From Scratch - Set filesystem type and volume label of new system partition

6) System reserved partition was created and formatted successfully:

Rebuild System Reserved Partition From Scratch - New system partition created and formatted
Rebuild System Reserved Partition From Scratch - New system partition created and formatted

7) Quit from Emergency Boot Kit Partition Manager to the main menu:

Rebuild System Reserved Partition From Scratch - Quit to the main menu
Rebuild System Reserved Partition From Scratch - Quit to the main menu

8) Run Emergency Boot Kit File Manager:

Rebuild System Reserved Partition From Scratch - Run Emergency Boot Kit File Manager
Rebuild System Reserved Partition From Scratch - Run Emergency Boot Kit File Manager

9) Insert Windows Installation DVD to the DVD reader. Press Alt+F1 to change disk on the left panel. Choose your DVD reader from the list (C: in this example):

Rebuild System Reserved Partition From Scratch - Choose Windows DVD On The Left Panel
Rebuild System Reserved Partition From Scratch - Choose Windows DVD On The Left Panel

10) Press Alt+F1 to change disk on the right panel. Choose your 100 MB system partition from the list (E: in this example):

Rebuild System Reserved Partition From Scratch - Choose System Reserved Partition On The Right Panel
Rebuild System Reserved Partition From Scratch - Choose System Reserved Partition On The Right Panel

11) Make sure input focus is on the left panel (press TAB if necessary). Navigate to boot folder using arrow keys. Then press F5 to open copy dialog. Confirm copying by pressing ENTER.

Rebuild System Reserved Partition From Scratch - Copy Boot folder
Rebuild System Reserved Partition From Scratch - Copy Boot folder

12) Navigate to bootmgr file using arrow keys. Then press F5 to open copy dialog. Confirm copying by pressing ENTER.

Rebuild System Reserved Partition From Scratch - Copy Bootmgr file
Rebuild System Reserved Partition From Scratch - Copy Bootmgr file

13) Press TAB to switch input focus to the right panel. Enter boot folder using ENTER key.

Rebuild System Reserved Partition From Scratch - Enter Boot folder
Rebuild System Reserved Partition From Scratch - Enter Boot folder

14) Navigate to the bcd file using arrow keys. Then press F8 to delete it. Confirm deletion by pressing ENTER.

Rebuild System Reserved Partition From Scratch - Delete BCD hive
Rebuild System Reserved Partition From Scratch - Delete BCD hive

15) Press F10 or click Quit in the bottom hint bar to quit Emergency Boot Kit File Manager:

Rebuild System Reserved Partition From Scratch - Quit Emergency Boot Kit File Manager
Rebuild System Reserved Partition From Scratch - Quit Emergency Boot Kit File Manager

16) Run Emergency Boot Kit Mount & Boot Center from the main menu:

Rebuild System Reserved Partition From Scratch - Run Mount and Boot Center
Rebuild System Reserved Partition From Scratch - Run Mount and Boot Center

17) Make sure that Windows Loader in the system reserved partition is marked to be called by BIOS and also that your main Windows installation is [x] marked in context of that loader. Then press OK.

Rebuild System Reserved Partition From Scratch - Configure Mount and Boot Center
Rebuild System Reserved Partition From Scratch - Configure Mount and Boot Center

18) Done. Eject Windows Installation DVD from the DVD reader and reboot to Windows.

Rebuild System Reserved Partition From Scratch - Done
Rebuild System Reserved Partition From Scratch - Done