How to stop Windows 10 or 11 from turning off your screen
This tutorial will show you step by step how to stop Windows 10 or 11 from turning off your screen automatically.
Methods:
How to stop Windows 10 from turning off your screen
1. Click on the Windows start menu button.
2. Click on Settings.
You can also right-click on the Windows start menu button and then click on Settings.
You can also press the Windows 
+ I keys on your keyboard to open settings in Windows 10.
3. Click on System.
4. Click on Power & sleep located in the left menu.
5. Under Screen, you click on the drop-down menu and select Never. If you're using a laptop, you'll see a second drop-down menu, and there you should also select Never.
That's it! Windows 10 will no longer turn off your screen automatically.
Note: If your PC is set to automatically sleep, your screen will also turn off when it goes to sleep. You can find the settings for this on the same screen as the settings for the screen.
How to stop Windows 11 from turning off your screen
1. Right-click on the Start menu button and then click on Settings. You can also press the Windows + I keys on your keyboard to open settings.
2. Click on System. Note: You may need to click on the ≡ menu button in the top left corner to open a menu and see the System option.
3. Click on Power & battery.
4. Click on Screen and sleep.
5. Under Screen and sleep, you click on the drop-down menu and select Never. If you're using a laptop, you'll see a second drop-down menu, and there you should also select Never.
That's it! Windows 11 will no longer turn off your screen automatically.
Related:
How to disable your PC's power button in Windows 10 and 11
How to keep your laptop on when the lid is closed on Windows 11