Dism /Unmount-Image /MountDir:"C:\Mount" /Commit
Use DISM to inject the language pack.
dism /image:"C:\mount" /Add-Package /PackagePath:"C:\offline_lp[language].cab" windows 11 language pack download offline
dism /image:"C:\mount" /Set-SKUIntlDefaults /lang:fr-FR windows 11 language pack download offline
Once you have the .cab file (e.g., Microsoft-Windows-Client-Language-Pack_x64_fr-fr.cab ), use one of the following methods to install it: Method 1: Using Lpksetup (Easiest) windows 11 language pack download offline