The desktop screen can suddenly go upside down because Windows 8 includes the auto-rotation feature and a set of keyboard shortcuts that users can accidentally press while playing games to change the orientation of the screen. Microsoft included this feature in Windows 8 because it designed the operating system for use on tablets in addition to desktop computers.
The auto-rotation feature is turned on by default in Windows 8, but it’s possible to negate its function by locking the screen from the brightness control menu, which can be accessed by pressing the Windows and I keys at the same time. Other options to disable this feature include using a keyboard shortcut to toggle it off, disabling it via the user interface or modifying a value in the Windows registry. To reset the screen orientation, press the Control, Alt and Up Arrow keys simultaneously.
To disable the auto-rotation feature via keyboard, press the Windows and O keys at the same time. To disable it via the user interface, right-click on the desktop, select the Screen Resolution option, uncheck the box next to the Allow the Screen to Auto-Rotate option, and click OK. To disable the function via registry, press the Windows and R keys at the same time, type “regedit” in the field and click OK. Press F3 to open the search dialog box, type “autorotation” in the search field and right-click on the Enable value. Select the Modify option from the context menu, type 0 in the Value Data field and click OK.