When running the integrated backup software – Backup and Restore (Windows), you may encounter error 0x80780166. This post explains how to fix the Windows backup error. In addition to the Windows snapshot tool, you can use third-party software to back up your operating system.
Several users expressed concerns about the 0x80780166 error when backing up Windows 10. They have used the Windows snap backup tool hundreds of times and never encountered this problem.
If you encounter the same error message 0x80780166, we have some working tips for you. To be more specific, below you will find a set of possible repair strategies that other users in a similar situation have successfully used to solve the problem.
What is the cause of error code 0x80780166?
So, what can cause this Windows backup error 0x80780166? Actually, there are many reasons why Windows backup error 0x80780166 occurs. We have listed some of them here.
- Corrupted system files
- Incorrect setting of the “Volume Shadow Copy” feature status.
- Corrupted data in the WindowsImageBackup folder.
- Corruption of the underlying file.
Whatever the cause, the most important thing is to fix Windows backup error 0x80780166. So, in the next section, we will show you how to fix Windows 10 backup error 0x80780166.
What should I do when I get the error 0x80780166?
Set the SSV service status to Automatic.
The most common cause of error code 0x80780166 is a faulty instance of the Volume Shadow Copy service (commonly known as VSS service). It is likely that the backup operation cannot be completed because the VSS service startup type is set to Manual.
Several users who also encountered this problem reported that they were finally able to resolve it by changing the Volume Shadow Copy service startup type from Manual to Automatic. After that, most of the affected users reported that they were able to complete the backup process without encountering error code 0x80780166.
Here are brief instructions on how to change the status type of the Volume Shadow Copy Service to Automatic:
Note: These instructions work regardless of the operating system version in which the problem occurred.
- Press Windows + R to open the Run dialog box. Type “service.msc” in the “Run” field and press “Enter” to open the Services window.
- While in the Services window, scroll through the list of (local) services and look for “Volume Shadow Copy”. Right-click and select Properties from the context menu.
- While in the properties screen of the Volume Shadow Copy service, select the General tab from the list of menu items and change the startup type to Automatic. Then click “Apply” to save your changes.
- Reboot your computer and repeat the action that caused error code 0x80780166 on the next boot.
If the same problem persists, proceed to the next method.
Clean up the WindowsImageBackup folder.
It turns out that this particular problem can occur when the disk where the user is trying to back up already contains files leftover from a previous backup. In most cases, this error code occurs when a previous backup operation was interrupted or there was not enough space to complete it.
Several users who found themselves in a similar situation confirmed that they were able to solve the problem by accessing the drive where they were trying to save the backup and deleting the contents of the Windows Image Backup windowsimagebackup folder. After this and repeated attempts, most of the users involved stated that the problem no longer existed.
Here are some steps you can take to remove windowsimagebackup folder to fix error code 0x80780166 :
- Open File Explorer and navigate to the drive where you just tried to back up.
- Find the WindowsImageBackup folder there and double-click it to open it. Note that this folder is hidden by default. If you don’t see it, go to the “View” tab at the top of the screen and check the “Hidden Items” box.
- When the hidden folders are visible, go to the WindowsImageBackup folder, select each file and delete everything until the folder is empty.
- Restart the backup process and see if the problem is resolved.
If the same error code 0x80780166 is still displayed, go to the next possible solution below.
Running the SFC and DISM scanners.
According to various user reports, this problem can also occur due to corrupted system files that somehow interfere with the backup process. It turns out that in such situations, you can fix error 0x80780166 by running some utilities that can fix logical errors and corrupt system files: DISM (Deployment Image Servicing and Management) and SFC (System File Checker).
Note that both tools are useful in situations caused by errors in system files, but they have different approaches to how they deal with corrupted files. For example, SFC is better able to fix logical errors because it relies on a locally cached copy when it is necessary to replace corrupted items with clean copies. On the other hand, DISM is better able to fix faulty operating system components and uses the Windows Update (WU) component to download new copies that are used to replace corrupt files.
Both utilities are useful in their own way, so we recommend running both if you encounter error 0x80780166 and previous patches didn’t help. Here’s how you should proceed:
- Open the “Run” dialog box by pressing Windows + R. Then type “cmd” in the text menu and press Ctrl + Shift + Enter to open a command prompt with administrative privileges. When you see UAC (User Account Control), click “Yes” to grant administrator privileges.
- In the expanded CMD window, type the following command and press Enter to start the DISM scan:
- Dism.exe /online /cleanup-image /scanhealth
Dism.exe /online /cleanup-image /restorehealth
- Note: Note that DISM actively uses Windows Update to download clean copies of the files to be replaced. Make sure you have a reliable Internet connection before you start this process. The first command (scanhealth) is used to scan the system for inconsistencies and the second command (restorehealth) is used to replace the inconsistencies found in the first scan.
- After the DISM scan is complete, restart your computer and wait for the next boot sequence.
- After the next full boot, run step 1 again to open another extended command line, then type the following command and press Enter again to start another SFC scan:
- Note: Note that it is not recommended to abort the process once the SFC scan has started.
This will expose your system to further logical errors in the future.
- Reboot your computer and see if error 0x80780166 is resolved.
If the problem persists, move on to the next possible solution below.
Use a system recovery utility
If the 0x80780166 error persists and the problem occurred only after you performed a certain action that ended prematurely (with an unexpected shutdown, critical error, etc.), you can solve the problem by using the System Restore Utility to restore your computer to a healthy state where the error did not occur.
This tool can use snapshots to restore your computer to a previous state. Note that by default, Windows is set to create new snapshots for every important event on your PC (application installation, important update, security check, etc.) If you haven’t changed the default behavior, you probably have a lot of snapshots.
Before you start following the instructions below to bring your machine back to an earlier date, remember that any changes made since creation will be lost. This means that any application, user settings, or anything else that was forced during this period will be undone.
If you decide to restore the system, here’s a step-by-step guide:
- Press the Windows + R keys to open the Run dialog box. While in the text box, type “rstrui” and press Enter to open the System Restore Wizard.
- While in the System Restore Wizard, click Next at the first prompt to move to the next menu.
- Next, select the restore point dated before the first backup attempt and click Next to proceed to the last menu.
- To start the recovery process, simply click Finish, and then click Yes in the confirmation prompt to begin the recovery process.
- After a few seconds, the computer will reboot and the new state will be applied the next time you start the system.
- After the old state is enforced, try backing up the operating system again to see if the same error has occurred.
If error 0x80780166 still occurs when you later save the Windows version, proceed to the next method.
Performing a repair/cleanup installation
If you were unable to resolve the problem using one of the possible solutions listed above, it is possible that the problem is related to a corrupted system file that cannot be fixed in the traditional way. If this scenario applies, you may be able to solve the problem by resetting all operating system components to ensure that every case of corrupted system files is completely fixed.
Several Windows users who also had problems fixing error 0x80780166 have confirmed that the problem no longer occurs and that they were able to back up without problems after performing a restore installation or a clean installation.
If you want to do the procedure as quickly as possible and are not worried about losing data, a clean installation is the best solution. This targeted approach resets any Windows components that may have been affected by the corruption. However, the big drawback is that all personal files, including apps, games, user settings, and personal data, will also be lost (unless you back up your data with a third-party program).
A longer but effective method of keeping most of your files (including apps, games, and personal data) is to perform an onsite repair installation. Don’t forget, however, that you will need an installation media or create one if you don’t already have one.
Frequently Asked Questions
The most common cause of error code 0x80780166 is a failed instance of the Volume Shadow Copy service (commonly known as the VSS service). It is likely that the backup operation will not complete because the VSS service startup type is set to manual.
0x81000037: Windows Backup failed to read from a "ghost" copy on one of the backup volumes. This problem occurs when you are trying to back up a specific library or when you take the default Windows backup and restore settings.
- Start a Windows Server backup.
- Select Local Backup.
- In the Action pane, click Backup Once to run the Backup Once Wizard.
- On the Backup Configuration page, select Miscellaneous Options, and then click Next.
- On the Select Backup Configuration page, select Custom, and then click Next.
Click Start, select Administrative Tools, and then select Windows Server Backup. The Windows Server Backup console appears. In the Actions pane, click Backup Program. The Backup Wizard appears.
Mark Ginter is a tech blogger with a passion for all things gadgets and gizmos. A self-proclaimed "geek", Mark has been blogging about technology for over 15 years. His blog, techquack.com, covers a wide range of topics including new product releases, industry news, and tips and tricks for getting the most out of your devices. If you're looking for someone who can keep you up-to-date with all the latest tech news and developments, then be sure to follow him over at Microsoft.