[Note: After I entered the problem statement, I found this question, which is apparently the same problem. Maybe one of us will get a good answer...]

I have used the "Windows 7 File Recovery" tool under Windows 8 to create system image backups to an external USB hard drive. I built a new Windows 8.1 machine, and I want to create my first system image backup of that machine to the same USB hard drive. The "Windows 7 File Recovery" tool is gone in Windows 8.1, but wbAdmin is alive and well:

wbAdmin start backup -backupTarget:\\?\Volume{2a2b...994f} -allCritical -quiet

fails with this text displayed:

wbadmin 1.0 - Backup command-line tool
(C) Copyright 2013 Microsoft Corporation. All rights reserved.

Retrieving volume information...
This will back up (EFI System Partition),(C:),Recovery (300.00 MB) to \?\Volume {2a2b1255-3a86-11e3-be86-b8ca3a83994f}.
The backup operation to F: is starting.
Creating a shadow copy of the volumes specified for backup...
Summary of the backup operation:

The backup operation stopped before completing.
The backup operation stopped before completing.
Detailed error: ERROR - A Volume Shadow Copy Service operation error has occurred:
(0x8004231f) Insufficient storage available to create either the shadow copy storage file or other shadow copy data.

The EFI System Partition is 100 MB
The Recovery Partition is 300 MB
The C partition is 1.72 TB, NTFS, 218 GB used, 1.51 TB free
The destination drive is 1.81 TB, NTFS, 678 GB used, 1.15 TB free

I've fiddled with vssadmin resize shadowstorage, with no change in the error. vssadmin list shadowstorage displays:

Shadow Copy Storage association
For volume: (C:)\?\Volume{37a0...263}\
Shadow Copy Storage volume: (C:)\?\Volume{37a0...263}\
Used Shadow Copy Storage space: 2.39 GB (0%)
Allocated Shadow Copy Storage space: 2.81 GB (0%)
Maximum Shadow Copy Storage space: 531 GB (30%)

Shadow Copy Storage association For volume: (F:)\?\Volume{2a2...94f}\
Shadow Copy Storage volume: (F:)\?\Volume{2a2...94f}\
Used Shadow Copy Storage space: 334 GB (17%)
Allocated Shadow Copy Storage space: 337 GB (18%)
Maximum Shadow Copy Storage space: UNBOUNDED (922154758%)

(Yeah, the "percent calculation" for UNBOUNDED is seriously bogus.)

I've run SFC /verifyonly and it seems happy. I've verified that the new `Volume Shadow Copy" service starts when I start the backup operation.

Any suggestions?


1 Answer 1


Burned an MSDN tech support incident and just got off the phone with the support engineer. He reproduced this problem on a UEFI system with Windows 8.1 installed. It turns out that the -AllCritical qualifier to the wbAdmin command does not work on a UEFI system because Volume Shadow Service (VSS) can not create a shadow copy of the FAT32 EFI partition.

The solution is to explicitly back up the C partition (without the -allCritical option):

wbAdmin start backup -backupTarget:E: -include:C:

You can ignore the warning that "this backup cannot be used to perform a system recovery". Both the Recovery and EFI partitions are restored during the system restore operation. (Makes sense... they were created during the initial system installation, so Windows obviously knows how to create them again.)

Some notes related to this issue:

  1. Note that the "Recovery" partition is a misnomer. That partition is actually the boot partition. In a legacy (non-UEFI) system, the "System reserved" partition serves the same purpose.

  2. To manage the files on the "backup" drive, use the vssadmin command line tool. Specifically:

    • vssadmin list shadows shows the show copies (i.e. "backups") stored on your backup drive. Note that, while a backup is in progress, the shadow copy is listed as being on the drive being backed up. The backup operation first creates a volume shadow copy on the volume being backed up, and them moves the shadow copy to the backup drive.

    • vssadmin delete shadows lets you selectively delete old shadow copies from your backup drive.

  3. To restore a partition, attach the backup disk and boot from the Windows 8.1 distribution media. Select "Repair your computer", then "System image recovery". When the restoration process is done, your EFI and Backup partitions are also restored. (Or at least so claims the Microsoft engineer. I have not verified that this is correct.)

  4. Here are some links (courtesy of the Microsoft tech support guy) that may be helpful:


I've discovered that System Image Backup is, in fact present in Windows 8.1; bring up Control Panel/File History, and the link is at the bottom left corner of the window. Scott Hanselman has a blog entry on the subject.

  • Have you tested the restore? About to do so myself but thought I'd ask. Nov 19, 2013 at 22:18
  • @MarkBoltuc No, I haven't had the delightful opportunity to need to test this. Please post a comment to let us know if the theory actually works in practice! Nov 21, 2013 at 0:36
  • 1
    I've discovered that vssadmin delete shadows doesn't work as advertised. When I try to delete a shadow, it complains that "Snapshots were found, but they were outside of your allowed context" Nov 22, 2013 at 19:23

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