Replace D:\path\to\ with the actual location of your .cab file:

DISM /Online /Add-Package /PackagePath:D:\path\to\microsoftwindowsclientlanguagepackx64enus.cab

When deploying 1,000 new workstations via Microsoft Endpoint Configuration Manager (MECM) or MDT, you want a fully configured image. Adding the language pack during the task sequence (before the user logs in) ensures the first boot experience is perfect.

If you see this feature failing in Windows Update logs, it might be because the system is trying to repair a corrupted language resource or the component store (WinSxS) has inconsistencies. The system attempts to redownload the .cab to fix broken UI strings.

Mount your Windows image and add the language pack:

DISM /Mount-Image /ImageFile:C:\install.wim /Index:1 /MountDir:C:\mount
DISM /Image:C:\mount /Add-Package /PackagePath:D:\microsoftwindowsclientlanguagepackx64enus.cab
DISM /Unmount-Image /MountDir:C:\mount /Commit