How to rotate computer screen?

[talkingnonsense]

My children have somehow managed to rotate the screen 90* on my PC. I know how to rotate on an iPad but am completely stuck, can anyone help??

Presuming that you're on a Windows machine try pressing CTRL, ALT and then the each of the cursor keys in turn, the screen might very well flip around to various alignments...

Yay yay yay! So simple and worked first time. You are king!

If you right-click on the desktop, you may see a menu with 'graphic options...' and can then turn off 'hot keys' so accidental rotations don't happen again.

(needs to be a bit of desktop with no icons on it)