Press Ctrl + Shift + Refresh to rotate the screen 90°. Continue pressing Refresh until the screen is rotated to its normal position.
Open the system tray and click the settings gear at the top right.
Click Device on the left side of the window and click Display.
Click the dropdown for Orientation and set it to Standard.
Tip: If you're having trouble navigating due to a rotated screen, plug an external mouse in and adjust your grip on the mouse to match the screen's orientation. Use the mouse to easily move in the correct direction.