The default was US. Look in System Settings under Regional & Language (not Keyboard & Mouse, or font, or Input) Click Country/Region and select British English, make sure locale is changed to United Kingdom, and the Language to British English and that it is top of the list. If you're Christian, ensure the first day of the week is Sunday. The paper format should be A4, click Apply.
Now (the piece of resistance

) the good old keyboard layout, select your keyboard model, (mine is Labtec Internet and is missing from the list) and choose the layout from the left hand pane, choose vaiant, click Apply.
Finally the spell checker, select English (UK), click Apply. Restart and check.
Vive la difference!