Really! Whether you internet is broken, menus aren't working, you can't print, a program won't load, etc. A reboot fixes about 15% of all computer issues, please do it!
Windows Click Start button 
in lower left, then the power icon and select shutdown:
If it won't shutdown or that start button is missing, on a desktop or laptop hold the power button until it shuts off (5 seconds), or on a Surface hold volume down and power together until it turns off (don't slide down on the screen when it suggests it)
Chromebook users should just hit CTRL, 
(Refresh Button), Power Button.
Power it back up and see if your issue is resolved.