DISM

Repair system file corruption with the following commands in the order listed from an elevated command prompt.

	DISM.exe /Online /Cleanup-image /Scanhealth
	DISM /Online /Cleanup-Image /RestoreHealth
	DISM.exe /online /cleanup-image /startcomponentcleanup
	SFC /Scannow

Microsoft DISM Docs

Error Recovery:

0x800f081f - The source files could not be found.

	Use the "Source" option to specify the location of the files that are required to restore the feature. For more information on specifying a source location, see http://go.microsoft.com/fwlink/?LinkId=243077
	Run from elevated cmd box: DISM /Online /Cleanup-Image /StartComponentCleanup
	Run from elevated cmd box: DISM /Online /Cleanup-Image /AnalyzeComponentStore

You can use Group Policy to specify a Windows image repair source to use within your network. The repair source can be used to restore Windows features or to repair a corrupted Windows image.

Features on demand enables you to remove an optional feature from a Windows® image and then restore it later. You can disable optional features and remove files associated with those features from a Windows image using the Deployment Image Servicing and Management (DISM) tools. When you use the /Remove argument with the DISM /Disable-Feature option, the manifest files for the feature or Server role is maintained in the image. However, all other files for the feature are removed. This enables you to store, download, and deploy smaller images without losing features. Once the image has been deployed, users can enable the feature on their computers at any time by using features on demand to retrieve the required files from the repair source. For more information, see Enable or Disable Windows Features Using DISM.

Automatic corruption repair provides files to repair Windows if the operating system has become corrupted. Users can also use a specified repair source on your network or use Windows Update to retrieve the source files that are required to enable a feature or to repair a Windows image. For more information, see Repair a Windows Image.

Choose a Repair Source

You can use Windows Update to provide the files that are required to restore a Windows feature or repair a corrupted operating system. You can also configure Group Policy to gather the required files from a network location. Multiple source locations can be specified in the Group Policy.

Use Windows Update to restore optional features and repair Windows images

Windows Update will be used by default if it is allowed by the policy settings on the computer.

If you want to use Windows Update as a primary or backup source for files that are used to restore optional features or repair Windows images, you should make sure that your firewall is configured to allow access to Windows Update.

Use a network location to restore optional features and repair Windows images

You can use a mounted Windows image from a WIM file as a source to restore optional features and repair a corrupted operating system. For example, c:\test\mount\Windows. For more information about capturing a Windows image as a WIM file, see Capture Images of Hard Disk Partitions Using DISM.

Mounting a WIM image

If you need to make change to a WIM file, you will need to mount it properly on Windows using DISM, a command line that enumerates, installs, uninstalls, configures, and updates features and packages in Windows images.

Open an elevated command prompt window, and run the following command:

DISM /Mount-Wim /WimFile:"filename.wim" /index:1 /MountDir:"c:\temp"

Make sure the mounted directory is empty and has nothing in it, as the image will be mounted to that folder that you can browse through with File Explorer.

You can use a running Windows installation as a source to restore optional features by sharing the c:\Windows folder on your network.

You can use a Windows side-by-side folder from a network share or from a removable media, such as the Windows DVD, as the source of the files. For example, z:\sources\SxS.

You can use a Windows image (.wim) file on a network share as a source to restore optional features. You must specify the index of the Windows image in the .wim file that you want to use and you must use a Wim: prefix in the path to identify this file format. For example, to specify index 3 in a file named contoso.wim, type: Wim:\\network\images\contoso.wim:3.

Note

When specifying a source, only use RTM media regardless of whether the source is a WIM or a mounted Windows image. Refresh media has older file versions excluded from the media and the target operating system may need these files. Also, make sure the source is patched to the latest Cumulative Update. If the target OS is patched to a higher level than the source, adding features or repairing Operating Systems may fail because the target OS needs updated files that are not present in the source.

Set Group Policy

You can use Group Policy to specify when to use Windows Update, or a network location as a repair source for features on demand and automatic corruption repair.

Configure Group Policy for Feature on Demand

Open the group policy editor. For example, on a computer that is running Windows 10, from the Start screen, type Edit Group Policy, and then select Edit Group Policy to open the Group Policy Editor.

Click Computer Configuration, click Administrative Templates, click System, and then double-click the Specify settings for optional component installation and component repair setting.

Select the settings that you want to use for Features on Demand.

Maintaining a Repair Source

If you do not use Windows Update as the repair source for features on demand and automatic corruption repair, you should consider the following guidelines for maintaining a repair source.

Servicing updates

You should keep any repair source current with the latest servicing updates. If you are using an image from a WIM file for features on demand, you can use the DISM tool to service the image. For more information, see Mount and Modify a Windows Image Using DISM. If you are using an online Windows installation shared on your local network as a repair image, you should make sure that the computer has access to Windows Update.

Multilingual images

You must include all of the relevant language packs with your repair source files for the locales that your image supports. If you try to restore a feature without all of the localization components that the Windows installation requires for that feature, the installation will fail.

You can install additional language packs after a feature is restored.