It's Start, Systemsteuerung, Regions- und Sprachoptionen, second Tab called Sprachen, the button Details, first Tab called Einstellungen, and there select English as your language. You can change the keyboard later, if you can read again, what's on the screen...
Don't know for MacOS, sorry.
_________________________
cheers, Thomas new owner of the MK1 00123 MK2 12GB 090000815 (my first one) MK2a 040103735 (from 303) and ???