Many video drivers have "keystroke" combo's which can rotate the screen
on any PC, laptop or otherwise, so, every few months a question comes up
when someone (or someone's child) has rotated the screen accidentally
and can't get it back.

The best way to find out about this is to see if your pc has a video
driver utility (look in control panel) then, open that and look for
hotkeys to find out which does what... can be useful in a number of
circumstances.

Beverly Howard [MS MVP-Mobile Devices]