User Configuration > Administrative Templates > Microsoft Office 2016 > Language Preferences > Display Language
User
HKCU\software\policies\microsoft\office\16.0\common\languageresources
This policy setting affects the proofing tools link under the Editing language section. If you enable this policy setting you, you may enter the URL to another location where proofing tools may be downloaded. If you disable this policy setting the URL will be removed. If you do not configure this policy setting, the URL will remain available and point to the proofing tools site on Office.com.