Windows 10: How to Set 24-Hour Clock

How to switch between the 12 and 24 hour clocks in Windows 10:

Click on the time display in the taskbar.
Click on Date and time settings.
Under Formats, click Change date and time formats.
Set Short time to H:mm or HH:mm, depending on whether you want a leading zero. For example, H:mm would be 8:30 and HH:mm would be 08:30.
Set Long time to H:mm:ss or HH:mm:ss.
Close the window. The settings are applied as soon as you make a change.