Hello,
To install the 2016 server managements tools, a french windows need to have english installed in windows 10
But, the "download" button was not present after adding english in windows 10 version 1703
Here is the solution that worked for me:
Download the .CAB for your language at one of these sites:
https://www.itechtics.com/windows-10-version-1703-language-packs/
https://www.itechtics.com/windows-10-version-1709-language-packs-direct-download-links/
Install the .CAB with DISM:
Dism /online /Add-Package /PackagePath:\\yourserver\Software\Microsoft_Windows\win10una1703frapro_work_en-us_CAB\lp_38a2c8c87c52a0dbe0c1cbf98fe79377383063ec.cab
(this worked, but the language was not visible in windows's 10 menus)
Delete the language with LPKsetup:
lpksetup.exe /u en-us
Add the language again with LPKSETUP:
lpksetup
(browse for the .cab file, install)
The new language is now in windows's menus to switch it.