When you attempt to install .NET Framework 3.5 or any other optional feature using “Windows Features” (optionalfeatures.exe) dialog or using DISM command-line, error 0x800F0954 may popup.
After enabling .NET Framework 3.5 and clicking OK, the following error may appear:
Windows couldn’t complete the requested changes.
The changes couldn’t be completed. Please reboot your computer and try again.
Error code: 0x800F0954
The same error may occur when attempting to install additional speech recognition or supplemental fonts using Optional features in the Settings page or using DISM command-line. For instance, you run the following command to install .NET Framework 3.5 from an elevated or administrator Command Prompt.
DISM /Online /Enable-Feature /FeatureName:NetFx3 /All
After pressing ENTER, here is the full error message you might see:
Version: 10.0.16299.15
Image Version: 10.0.16299.192
Enabling feature(s)
[==========================100.0%==========================]
Error: 0x800f0954
DISM failed. No operation was performed.
For more information, review the log file.
The DISM log file can be found at C:\Windows\Logs\DISM\dism.log
The DISM.log file would show these entries/errors:
xxxx, Info DISM DISM Package Manager: PID=12956 TID=12296 Further logs for online package and feature related operations can be found at %WINDIR%\logs\CBS\cbs.log - CPackageManagerCLIHandler::ExecuteCmdLine xxxx, Error DISM DISM.EXE: DISM Package Manager processed the command line but failed. HRESULT=800F0954
And the CBS.log file would have recorded these errors:
xxxx, Info CBS DWLD:Failed to do Windows update search [HRESULT = 0x800f0954 - CBS_E_INVALID_WINDOWS_UPDATE_COUNT_WSUS] xxxx, Info CBS FC: WindowsUpdateDownloadFromUUP returns. [0x800F0954]
Note that the error 0x800f0954 refers to CBS_E_INVALID_WINDOWS_UPDATE_COUNT_WSUS which indicates that your system might have been configured to use a WSUS server (on your domain network) to get updates instead of connecting to Windows Update servers directly.