Just had an encounter with a user who needed their language updated. The UI Language was set to Korean – I wasn’t able to walk the user through updating it since I don’t read Korean either.
You supply a connection string for the target CRM Organization (Should support everything – CRM Online, On-Premise – just paste everything in the CRM url up to (but not including) the “/main.aspx”)
You can search for the user by Guid, Full Name or DomainName (aka User Name) (all the search fields auto add wildcards)
The tool returns a list of matching users – select the user to update, select the desired values for language code and click Update. Pretty basic and there are instructions for doing it, but I didn’t see anything so simple out there.
You can get the binaries here: Dynamics CRM User Language Update Tool
And the source code here: Dynamics CRM User Language Update Tool Source Code
(Note that you may need to have Windows Identity Foundation installed – this is a prerequisite of the CRM SDK)
This tool works with Dynamics CRM 2011, Dynamics CRM 2013, Dynamics CRM 2015, Dynamics CRM Online, and the forthcoming Dynamics CRM 2016 (ie everything 2011 and later)