VMM: VM-Template - Regional settings (Keyboard-Layouts)

$templatename = "<VM-Template-Name>"
 
$template = Get-SCVMtemplate | where {$_.Name  -eq "$templatename"} 
$settings = $template.UnattendSettings;
$settings.add("oobeSystem/Microsoft-Windows-International-Core/UserLocale","de-CH");
$settings.add("oobeSystem/Microsoft-Windows-International-Core/SystemLocale","de-CH");
$settings.add("oobeSystem/Microsoft-Windows-International-Core/UILanguage","en-US");
$settings.add("oobeSystem/Microsoft-Windows-International-Core/InputLocale","0807:00000807;0407:00000407;0409:00000409;0410:00000410");
$settings.add("oobeSystem/Microsoft-Windows-International-Core/InputLocale","0407:00000407");
$settings.add("oobeSystem/Microsoft-Windows-International-Core/InputLocale","0409:00000409");
Set-SCVMTemplate -VMTemplate $template -UnattendSettings $settings

More Information:

• KB: https://support.microsoft.com/en-us/help/2709539/regional-settings-default-to-english-when-deploying-a-virtual-machine
• Language Pack Default Values: https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-vista/cc766191(v=ws.10)
• Default Input Locales: https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-vista/cc766503(v=ws.10)