To change your monitor's screen from horizontal to vertical, click the "Desktop" app on Windows 8's Start screen to launch the Desktop, and then right-click on any blank space on the screen.

Any horizontal lines drawn on the screen though were stretched out - so if I had a window taking up a portion of the screen, a shadow of it would stretch all the way across the screen.<P>Obviously ...

If you see Horizontal red lines on screen in Windows 11/10, update or roll back Display Drivers, make sure the resolution and refresh rate match your monitor’s recommended settings.