When hotkeys or buttons are not operating, and the computer screen still doesn't function on Windows 10, the hotkeys may be disabled. In Windows 10, go to Visual options > > Hot keys > > Allow configuring device rotate hotkeys.
Windows 7
Step1
Right-click on your Desktop.
Step 2
Click "Screen Resolution."
Step 3
From the drop-down screen pick the orientation. When your preferred orientation is picked, press "Okay."
Video Card Control Panel

• Step.1 Right-click on your screen on the Video Card Control Panel
  Step.2 Tap on a control panel in the middle of the right-click button on your video card.
  Step.3 Select "Rotate View" from the video card control panel on the left screen.
  Step.4 Click on the radio button next to your desired orientation. To close the window, press' Send.'

Hope so above mentioned solutions for flip computer screen upside down is work for you.


Other Related Links
How To Flip Computer Screen