I tried editing credprovhost.dll.mui successfully following the steps earlier in the thread but somehow it doesn't work.
I'm on Windows 10 Home Edition in Swedish though so I edited credprovhost.dll.mui in the sv-SE folder in System32. That is, I edited the Swedish translation 'Annan användare' of 'Other user' in that file located under ID 100.
Somehow 'Annan användare' is still shown at the login screen. Does anyone know how to fix this?