I think that's for other versions of Windows hc. On my desktop running Windows 10, you right click on the time/date on the bottom right of the bar at the bottom of the screen and choose the second option from the top in the menu which appears. You will then find all sorts of options to adjust the display format of the date and time.
Chris38: I think you are being a bit unfair to Microsoft. If you installed Windows 10 yourself you would have been given this option during setup, but if you just clicked on next or whatever then you would get the default - American settings. If you bought a computer with it already installed then it's the fault of whoever installed it, not Microsoft.