Fix Error 0x800F0906 in Windows 8 or 8.1 (Historical)

Historical support note: Windows 8 reached end of support on January 12, 2016, and Windows 8.1 reached end of support on January 10, 2023. This guide is retained for existing legacy systems.

Error 0x800F0906 is associated with Windows being unable to download source files needed for a component or feature operation. Microsoft documents the code as CBS_E_DOWNLOAD_FAILURE in scenarios such as .NET Framework 3.5 installation on Windows 8/8.1.

The original version of this article treated the problem mainly as a Windows Update cache issue. That is not the most reliable diagnosis. First determine whether Windows can reach the required source, or provide a matching repair source.

1. Check network and Windows Update access

If the operation expects to download files from Windows Update:

Confirm that the PC has Internet access.
If the PC is managed by an organization, check whether Group Policy or WSUS settings prevent Windows from obtaining optional component files from Windows Update.
Retry the feature installation or DISM repair.

2. If you are enabling .NET Framework 3.5

Use installation media that matches the installed Windows release and specify its sources\sxs folder as the source.

For example, if the matching Windows media is mounted as D::

DISM /Online /Enable-Feature /FeatureName:NetFx3 /All /Source:D:\sources\sxs /LimitAccess

Do not use files from a different Windows release or architecture.

3. If DISM RestoreHealth reports the error

For component-store repair, DISM /Online /Cleanup-Image /RestoreHealth normally uses Windows Update as a repair source. If Windows Update cannot provide the required files, use a known-good repair source that matches the installed Windows image.

Microsoft documents the /Source option for specifying known-good files and /LimitAccess for preventing DISM from contacting Windows Update.

4. Avoid deleting update stores as the first step

Renaming SoftwareDistribution or catroot2 is sometimes used in Windows Update troubleshooting, but it does not address every 0x800F0906 case and should not be presented as the primary fix for a missing repair source.