As Microsoft changes Windows 10 to use more Features on Demand (FOD), there will be a much larger pull to have these updates come directly from Microsoft. Currently (2019.02), feature on demand updates don’t flow down to WSUS specifically from 1809. I’m not entirely sure why because there are Windows 10 FOD product groups (Windows 10 Feature on Demand, Windows 10 GDR-DU-FOD), but in looking at the updates that sync within those product groups, I only see updates for 1709 and lower and a few ambiguous updates without any version comments and all KB article links are 404 not found. This poses a problem for IT Administrators who use RSAT tools because as of 1809, the tools are now FODs (that supposedly stay installed now on each feature upgrade).

Languages also are part of these Features on Demand, so if you’re attempting to allow users to install language packs or writing tools, they now must be installed as a FOD so that they stay installed on each future upgrade.

While we wait for a more clearer picture from Microsoft how to utilize these new FODs in combination with WSUS, there is something you can do to help take away the inhibiting factors. You can temporarily switch Windows Update to not use WSUS, install your RSAT tools or any FODs, and then re-enable Windows Update to use WSUS. An example PowerShell code set for installing all RSAT tools would be (run from an administrative PowerShell prompt):

$UseWUServer = Get-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU" -Name "UseWUServer" | Select-Object -ExpandProperty UseWUServer
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU" -Name "UseWUServer" -Value 0
Restart-Service "Windows Update"
Get-WindowsCapability -Name "RSAT*" -Online | Add-WindowsCapability –Online
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU" -Name "UseWUServer" -Value $UseWUServer
Restart-Service "Windows Update"

You can adapt this PowerShell snippit to install anything while WSUS is momentarily removed and immediately re-applied after.

The GPO Method

There is however an alternative solution that is easier, better, accomplishes the same thing (yes, still going to Microsoft for FODs), and that is to set the Group Policy to go directly to Windows Update for optional features.

Computer Configuration > Policies > Administrative Templates >System > Specify settings for optional component installation and component repair

Set it to Enabled

Alternate source file path: <BLANK>
Never attempt to download payload from Windows Update: Disabled
Download repair content and optional features directly from Windows Update instead of Windows Server Update Services (WSUS): Enabled

Then you don’t have to worry and optional components will install without issue.

Until Microsoft makes these options easier with WSUS, it seems the only way is to go direct to the source.