If your Windows 11 computer turns the screen off or goes to sleep too quickly, you can change the timeout settings.
Open:
Settings > System > Power & battery
Expand:
Screen, sleep & hibernate timeouts
You can now change how long Windows waits before:
Turning off the screen
and:
Putting the computer to sleep
Choose the time you prefer from each drop-down menu.
On a laptop, you may see separate settings for when the computer is running on battery power and when it is plugged in.
If you do not want the computer to go to sleep automatically, select:
Never
for the sleep setting.
Changing these settings does not stop you putting the computer to sleep manually from the Start menu.