What should I do when the computer screen is upside down?

Two solutions are provided as follows:

1. desktop -- properties -- settings -- Advanced -- select the item of your video card, and then the graphic Property -- rotate -- 180 degrees;

2. generally, the PC supports reversing the screen. You can press "alt and CTRL" at the same time and press the arrow keys on the keyboard to rotate the display screen, for example, if you press Alt + Ctrl + down, your display screen will be reversed to see if you have inadvertently implemented this operation (try CTRL + ALT + ↓ and you may be able to return) is your machine Lenovo? Can you try this "Ctrl" + "Alt" + "↓" Display Screen rotation 90 degrees counterclockwise "Ctrl" + "Alt" + "→" the display screen is rotated 90 degrees clockwise. "Ctrl" + "Alt" + "↓": the screen is rotated 180 degrees. "Ctrl" + "Alt" + "↓": the screen is restored to normal use.