One option would be follow what is mentioned in the following blog post. This would ensure that the console is always opened with the correct language but wouldn't prevent them from changing it. You could then set a GPO or a DCM baseline in SCCM
to make sure that this regkey is always set correctly.
Microsoft is conducting an online survey to understand your opinion of the Technet Web site. If you choose to participate, the online survey will be presented to you when you leave the Technet Web site.