Why does my laptop go to sleep when I close the lid?
Because Windows' default "When I close the lid" action is Sleep, to save battery and keep a closed laptop from overheating. You can change it to "Do nothing" in Power Options. If the laptop still sleeps, the usual causes are the idle-sleep timer, a critically low battery, an IT policy, or the laptop's firmware.
Why Windows sleeps when you close the lid
Every Windows power plan has a setting called When I close the lid, and on laptops it's set to Sleep out of the box. That's a sensible default:
- Battery. A closed laptop is usually being carried, and sleeping saves the battery.
- Heat. A closed laptop cools less well, and one that keeps working in a bag can get very hot.
- Expectation. Most people expect a closed laptop to be "off".
How to change it
Open Control Panel → Power Options → Choose what closing the lid does and set Plugged in to Do nothing. The full steps, a one-line command and the risks are in how to keep a laptop running with the lid closed.
Why it can still sleep after you change it
- The idle timer. "Do nothing" only changes the lid. Windows still sleeps after its normal idle time (often 15–30 minutes), lid open or closed, unless you also turn that off or keep the PC awake.
- On battery. The lid setting has separate values for plugged in and on battery. If you only changed one, the other still sleeps.
- Critically low battery. Windows always acts on a critical battery level.
- Work or school PCs. Your organization's IT can lock power settings; your change may be ignored or reset.
- Firmware. A few laptops sleep on lid close regardless of the Windows setting. Test with a short session first.
With an external monitor
If you dock a laptop and close it to use an external screen, set the plugged-in lid action to "Do nothing"; otherwise Windows sleeps even though a monitor is connected.
Is it safe to run a laptop with the lid closed?
Usually, if it's plugged in and on a hard, open surface. Don't put a running laptop in a bag or on a bed, and remember that a permanent "Do nothing" setting stays on until you change it back.