Power User Insights: The Cure for Failing VSS: Acronis VSS Doctor

Acronis VSS Doctor

Power User Insights are guest blogs written by advanced users who share their tips, tactics and techniques so you can get the most out of Acronis products.

Paul Larini has been using Acronis True Image and making it work in WinPE for many years. He developed MustangPEBuilder to make customizing WinPE with Acronis software easy for thousands of users.


Backups are invaluable for getting your system up and running when a software program fails or gets corrupted. But what can you do when a Windows process that is key to creating backups stops working properly?

Many backup applications – including Acronis True Image, Acronis Backup, and even Windows itself – use Microsoft Volume Shadow Copy Service (VSS) when creating backup image files. That’s because VSS allows the computer to continue being used during backup operations, enhancing the user experience. But like any other program, things can happen to prevent VSS from working properly, causing your backup to fail.

Diagnosing and correcting VSS problems can be complex, which is where Acronis VSS Doctor can be of help. Here’s how you can use the free Acronis VSS Doctor tool to fix what ails your system.

To begin, download the free Acronis VSS Doctor. It is an .exe file that runs as a stand-alone application, so once you’ve downloaded the file, right click on the file and select “Run as administrator” as shown below.

Acronis VSS Doctor - Download

Once the Acronis VSS Doctor screen appears, click on the “Start diagnostic” button at the bottom of the screen to run the tool.

Acronis VSS Doctor Start diagnostic

After the diagnostic scan runs, the tool will display the results of each scan task.

Acronis VSS Doctor Results

Clicking on “Show details” will display the results of the associated test scan.

Acronis VSS Doctor Show details

Acronis VSS Doctor displays any issues found during a scan and you can correct most common issues by simply clicking the “Fix issues” button.

Acronis VSS Doctor Fix issues

After you select “Fix issues,” a warning will appear.

Acronis VSS Doctor Fix issues


As noted in the illustration, resizing shadow storage to a sufficient size for backup creation will remove any existing shadow copies. Any Windows System Protection restore points on the computer will be removed.

After “Fix issues” is selected and run, you’ll need to run the diagnostic scan again to verify the fix was a success.

Acronis VSS Doctor

Windows 7 systems have a hidden 100 MB system partition that can sometimes become corrupted and cause VSS to fail, which results in a failed backup. To resolve this issue, you’ll need to use the Microsoft chkdsk utility command chkdsk /f /r on the hidden partition. Hidden partitions do not have a drive letter, but you need a drive letter to run the chkdsk utility. Thankfully Acronis VSS Doctor provides an easy way to assign a drive letter to a hidden partition.

Acronis VSS Doctor Windows 7

Note in the screenshot above that the hidden partition is listed but has no drive letter assignment. Clicking “Assign drive letter” will assign the next available drive letter to the partition so that chkdsk utility can be used to fix existing corruption.

Acronis VSS Doctor Assign drive letter

After running chkdsk on the partition it will be necessary to remove the drive letter you assigned. Simply click “Unassign drive letter” to remove the drive letter.

You will receive a warning message when choosing “Unassign drive letter.” This is normal, so just click “Yes” to remove the drive letter.

Acronis VSS Doctor Unassign drive letter

After removing the drive letter, run the “Start diagnostic” scan again to check for any additional issues.

A diagnostic scan resulting in an exclamation mark displayed for the Event Log scan will show events in the log listed along with Google search links for more information on correcting such errors.


Download Acronis VSS Doctor Now!