You mean rotating the image to be ether horizontal or vertical?
Looking at the computer i don't see why it should have that feature. Auto rotation requires it to have a sensor the detects motion and orientation. All smartphones has this, but an all in one PC shouldn't waste money implementing that.
It doesn't even look like it has a stand that is able to rotate the screen vertical.
If it uses intel graphics you should be able to rote the image by hitting control + alt + right or left. Else it should be in intel graphic center. (or whatever graphic center you use. Like catalyst if you are using a AMD GPU.)
In the Notification Center in Win 10 there is an option for rotation lock. Is that what you're looking for?