You put it to sleep and you go to bed. At two in the morning the fans spin up and the room lights up. Nobody touched it.
It is not haunted and it is not a virus. Something on your PC has permission to wake it, and Windows will tell you exactly what if you ask.
I asked on this machine and got a number I did not expect. Sixteen devices could wake it and six are currently allowed to.
Four commands, and the whole answer
Every one of these reads only. Nothing is changed.
⚡ Documented by Microsoft in its powercfg reference, `/lastwake` "Reports information about what woke the system from the last sleep transition".
⭐ And `/waketimers` "Enumerates active wake timers", which is the scheduled half of the problem.
⚠️ Open Terminal and run all four:
powercfg /lastwake
powercfg /waketimers
powercfg /devicequery wake_armed
powercfg /availablesleepstates⛔ The last one is the interesting one, and almost nobody runs it.
⚠️ We could not find a Microsoft consumer page that explains any of this, which is why the answer sits in a command line rather than in Settings.
Ours: what those four returned here
Four answers, and the last one changes how you think about all of it.
Ours, read on this machine. Six devices are armed to wake it, out of sixteen that could be.
⚡ No wake timers are currently set. So nothing scheduled is due to bring it back.
⭐ And the last wake recorded no source at all. Windows knows it woke and does not know why, which is more common than you would like.
⛔ Ours, and this is the one that matters: this PC reports no S3 sleep at all. The firmware does not support it, and Windows says so plainly.
Your PC may not really sleep any more
The part that explains the whole complaint.
⚠️ Only one standby state is available here. It is S0 low power idle, usually called modern standby.
⛔ Modern standby is not sleep in the old sense. The machine keeps running quietly, which is exactly why things can wake it up.
⚡ On an older PC with real S3 sleep, almost nothing could. The machine was genuinely off, apart from the memory.
⭐ So if your laptop wakes in a bag, or drains overnight, this is why. It was never fully asleep to begin with.
Turning the culprits off
Two settings, and both are reversible.
⭐ Run the wake_armed command and read the list. Network adapters and mice are the two that catch most people.
⚡ Turn one off with this, using the name exactly as the list printed it:
powercfg /devicedisablewake "Device Name Here"⚠️ The mouse is the usual suspect on a desk. A nudge. A cat. A lorry going past.
⛔ The network adapter is the usual suspect overnight. Wake on LAN is on by default on a lot of machines and almost nobody uses it at home.
The timers, which are the other half
Different mechanism, same result.
⚡ A wake timer is a scheduled job with permission to wake the PC, usually maintenance or an update.
⭐ Windows runs automatic maintenance in the early hours by default. That is why two in the morning is such a common time.
⚠️ You can stop timers waking it in Power Options, under advanced settings, sleep, allow wake timers.
⛔ Ours, and the order matters: turn the devices off first and only then the timers. Timers are usually doing something useful.
When it is not a wake at all
Three look-alikes worth ruling out.
⚠️ A screen that goes dark and comes back is not a wake. Windows keeps two separate timeouts and people only ever find one.
⭐ A PC that restarts rather than wakes has been updating. That is a different behaviour with a different setting.
⛔ And a machine that seems to start itself from off is usually not off at all. Fast Startup means Shut down is not a full shutdown.
⚡ I would run lastwake first thing in the morning, because the answer is overwritten by the next wake.
What not to do about it
Three fixes people reach for that cost more than they give.
⛔ Do not disable sleep entirely. You get a machine that runs all night instead of one that wakes occasionally.
⚠️ Do not turn off automatic maintenance. It is doing updates, cleanup and checks that you want done.
⭐ And do not go into the BIOS first. Everything here is reversible from Windows. Firmware settings are not always labelled clearly.
Status: read against Microsoft's powercfg documentation, 27 August 2026, on Windows 11. Wake sources, timers, armed devices and available sleep states were all read here. ⛔ Nothing was changed.
How do I find out what woke my PC?
Run `powercfg /lastwake` in Terminal first thing, before anything else wakes it. It reports what caused the last wake. Then run `powercfg /devicequery wake_armed` to list every device currently allowed to wake it, and `powercfg /waketimers` for anything scheduled to.
Why does my PC wake up at 2am?
Because Windows runs automatic maintenance in the early hours by default, and it is allowed to wake the machine to do it. You can stop timers waking your PC in Power Options, under advanced settings and sleep. Turn off the devices allowed to wake it first, because those are usually the ones you never wanted.
Why does my laptop drain overnight when it is asleep?
Because it may not really be asleep. Many modern PCs only support S0 low power idle, called modern standby, where the machine keeps running quietly rather than switching off. Run `powercfg /availablesleepstates` and see whether S3 is listed as unavailable on yours.
Should I just turn sleep off?
No, that swaps an occasional wake for a machine running all night. Turn off the specific devices allowed to wake it instead. The list is usually short, the change is one command, and putting it back is the same command with a different name.
The Short Version
- Four powercfg commands answer this, and all four only read.
- On this PC, six devices are armed to wake it out of sixteen that could be.
- The mouse is the usual daytime culprit, the network adapter the overnight one.
- Turn one off with `powercfg /devicedisablewake` and the name as printed.
- Wake timers are the other half. Windows maintenance runs in the early hours.
- Run `powercfg /availablesleepstates` and look for S3.
- If S3 is unavailable, your PC never really sleeps. It idles quietly instead.
- Do not disable sleep altogether. Turn off the specific culprits.
Where to Next
Phones answer calls by themselves too, which is far more alarming and much simpler to fix. It is usually one accessibility setting.
Phones do a version of this too, and it is a schedule rather than a device waking them. A Focus that switches itself on has a cause worth knowing.
Run the four commands above before you change anything. All four read only, and together they name your culprit in about a minute.
Run lastwake first thing in the morning, before you touch anything else. The answer is overwritten as soon as the machine wakes again.
Then disable the one or two devices you did not want waking it, starting with the network adapter and the mouse.
If the screen going dark is what actually bothers you rather than the machine waking, that is a separate pair of settings. Windows keeps two timeouts, not one.
If your lastwake named something odd, put it in the comments. Some of the answers that command gives are genuinely strange.
Isaac Smith is the founder and editor of PC Glance, a website that covers computers, laptops, and technology. He is a tech enthusiast and a computer geek who loves to share his insights and help his readers make smart choices when buying tech gadgets or laptops. He is always curious and updated about the latest tech trends.