Repair Windows Server 2016 Error 0x800f081f

Run this function in PowerShell as Administrator:

function resetWindowsUpdate{
    # Source: https://learn.microsoft.com/en-us/troubleshoot/windows-client/installing-updates-features-roles/additional-resources-for-windows-update
    write-host 'Resetting Windows updates...'
    $originalLocation=get-location
    stop-Service wuauserv -force
    stop-Service cryptSvc -force # This may not work due to certain antivirus dependencies
    stop-Service bits -force
    stop-Service msiserver -force
    Rename-Item "$env:systemroot\SoftwareDistribution" SoftwareDistribution.bak
    if((get-service cryptSvc -ea silentlycontinue).status -eq 'Stopped'){
        Rename-Item "$env:systemroot\System32\catroot2" Catroot2.bak
    }else{
        write-warning "$env:systemroot\System32\catroot2 was not renamed."
    }
    set-location "$env:windir\system32"
    regsvr32 c:\windows\system32\vbscript.dll /s
    regsvr32 c:\windows\system32\mshtml.dll /s    
    regsvr32 c:\windows\system32\msjava.dll /s
    regsvr32 c:\windows\system32\jscript.dll /s    
    regsvr32 c:\windows\system32\msxml.dll /s    
    regsvr32 c:\windows\system32\actxprxy.dll /s    
    regsvr32 c:\windows\system32\shdocvw.dll /s    
    regsvr32 wuapi.dll /s    
    regsvr32 wuaueng1.dll /s    
    regsvr32 wuaueng.dll /s    
    regsvr32 wucltui.dll /s    
    regsvr32 wups2.dll /s    
    regsvr32 wups.dll /s    
    regsvr32 wuweb.dll /s    
    regsvr32 Softpub.dll /s    
    regsvr32 Mssip32.dll /s    
    regsvr32 Initpki.dll /s    
    regsvr32 softpub.dll /s    
    regsvr32 wintrust.dll /s    
    regsvr32 initpki.dll /s    
    regsvr32 dssenh.dll /s    
    regsvr32 rsaenh.dll /s    
    regsvr32 gpkcsp.dll /s    
    regsvr32 sccbase.dll /s    
    regsvr32 slbcsp.dll /s    
    regsvr32 cryptdlg.dll /s    
    regsvr32 Urlmon.dll /s    
    regsvr32 Shdocvw.dll /s    
    regsvr32 Msjava.dll /s    
    regsvr32 Actxprxy.dll /s    
    regsvr32 Oleaut32.dll /s    
    regsvr32 Mshtml.dll /s    
    regsvr32 msxml.dll /s    
    regsvr32 msxml2.dll /s    
    regsvr32 msxml3.dll /s
    regsvr32 Browseui.dll /s    
    regsvr32 shell32.dll /s    
    regsvr32 wuapi.dll /s    
    regsvr32 wuaueng.dll /s    
    regsvr32 wuaueng1.dll /s    
    regsvr32 wucltui.dll /s    
    regsvr32 wups.dll /s    
    regsvr32 wuweb.dll /s    
    regsvr32 jscript.dll /s
    regsvr32 atl.dll /s    
    regsvr32 Mssip32.dll /s
    netsh winsock reset
    start-service wuauserv
    start-service cryptSvc
    start-service bits    
    start-service msiserver
    bitsadmin.exe /reset /allusers
    DISM.exe /Online /Cleanup-image /Restorehealth    
    set-location $originalLocation
    write-host 'Done.'
}

resetWindowsUpdate

Symptom:

PS C:\Windows\system32> Install-WindowsFeature DHCP -IncludeManagementTools
Install-WindowsFeature : The request to add or remove features on the specified server failed.
Installation of one or more roles, role services, or features failed.
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 https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/configure-a-windows-repair-source?view=windows-11. Error: 0x800f081f
At line:1 char:1
+ Install-WindowsFeature DHCP -IncludeManagementTools
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (@{Vhd=; Credent...Name=localhost}:PSObject) [Install-WindowsFeature],
Exception
+ FullyQualifiedErrorId : DISMAPI_Error__Failed_To_Enable_Updates,Microsoft.Windows.ServerManager.Commands.AddWind
owsFeatureCommand

Success Restart Needed Exit Code Feature Result
------- -------------- --------- --------------
False No Failed {}

Resolution:

# Clean up Windows Component Store, aka WinSXS (C:\Windows\winsxs)
DISM /Online /Cleanup-Image /StartComponentCleanup # fix WinSXS
# SFC /SCANNOW # fix corrupted system files
DISM /Online  /Cleanup-Image /AnalyzeComponentStore # check WinSXS
# SFC /SCANNOW
# Restart-Computer # reboot to render changes effective

# Perform Windows Repair using Microsoft Windows Update sources (may not work):
# Run Restore Health after reboot
DISM /Online /Cleanup-Image /RestoreHealth

# PowerShell native command to restore health
Repair-WindowsImage -Online -RestoreHealth

# Perform Windows Repair using Windows ISO as the source (works better):

# Specify ISO Path to automatically generate the rest of the other variables
# Obtain ISO from Microsoft at https://www.microsoft.com/en-us/evalcenter/evaluate-windows-server-2016/
# https://software-static.download.prss.microsoft.com/pr/download/Windows_Server_2016_Datacenter_EVAL_en-us_14393_refresh.ISO
$isoPath="\\it-fs2\it$\Software\ISO's\SW_DVD9_Win_Server_STD_CORE_2016_64Bit_English_-4_DC_STD_MLF_X21-70526.iso"

# Autogen variables:
$isoMount=Mount-DiskImage $isoPath -PassThru
$driveLetter=($isoMount | get-volume).DriveLetter
$wimPath="$driveLetter`:\sources\install.wim:1"
$logPath="C:\Temp\dism-repair-windows.log"

# Restore Windows Health using provided ISO:
dism /online /cleanup-image /restorehealth /source:WIM:$wimPath /limitaccess # non-native PowerShell command
# Repair-WindowsImage -Online -RestoreHealth -Source $wimPath -LimitAccess -LogPath $logPath


# Dismount ISO when done
Dismount-DiskImage -ImagePath $isoPath

Sample Output:

# Failure scenario

PS C:\Windows\system32> dism /online /cleanup-image /restorehealth

Deployment Image Servicing and Management tool
Version: 10.0.14393.3085

Image Version: 10.0.14393.3085

[==========================100.0%==========================]
Error: 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 informat
ion on specifying a source location, see https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/configure-a-windows-repair-source?view=windows-11.

The DISM log file can be found at C:\Windows\Logs\DISM\dism.log

# Success scenario

PS C:\Windows\system32> DISM /Online /Cleanup-Image /StartComponentCleanup

Deployment Image Servicing and Management tool
Version: 10.0.14393.3085

Image Version: 10.0.14393.3085

[=====                      10.0%                          ]

PS C:\Windows\system32> dism /online /cleanup-image /restorehealth

Deployment Image Servicing and Management tool
Version: 10.0.14393.3085

Image Version: 10.0.14393.3085

[==========================100.0%==========================]Done...