Laptops have afforded us a level of flexibility in our work that could only be dreamed of a few decades ago. At any point, you can be working on a laptop, whether you're riding a train or sitting at a library, and just close your laptop to continue working on it later.

Well, at least in theory. Closing your Windows 11 laptop puts it to sleep so it saves battery, and you can pick up where you left off. But if you've been relying on this method to keep your unsaved work alive, you could be in for some bad news, and you need to change your habits.

Windows sleep mode is not good

It gets messy

The whole point of sleep mode is that it shuts down most of the activity on the computer, holding just a few background tasks and saving the current state to memory so you can easily resume it later. The background tasks running in sleep mode should be absolutely minimal — an internet connection is kept, so in theory you can still get notifications from apps, and Windows updates can be downloaded in the background, for example.

You might think these things don't make a big difference, but they do. Battery usage in sleep mode isn't as small as you might expect, and in fact, your computer's fan may even need to speed up while it's sleeping due to background tasks. I've had situations where I put my laptop in my bag only to find later that it keeps getting warmer because it's in a closed space and apparently still running the fan because it's performing some kind of task.

But even if your laptop isn't getting toasty in your bag, there's a good chance that battery is draining faster than you think. Windows does a bad job of slowing down its tasks in sleep mode, and x86 processors (such as those from Intel and AMD) don't handle background tasks nearly as efficiently as Arm processors tend to.

That's why there are multiple reports of people losing their work because their laptop died while they weren't using it. If your battery runs out while the computer is in this sleep mode, you may no longer be able to go back to the previous state, meaning your unsaved work is lost.

It wasn't always like this

Modern Standby is the problem

The reason this happens is due to a feature called Modern Standby, which Microsoft introduced in Windows 10 as a continuation of the Connected Standby feature in Windows 8.1. Modern Standby is also known as S0 sleep, and it's a form of standby mode that allows the system to wake up instantly in response to certain events, such as interacting with the keyboard, receiving a network packet, or other important hardware interrupts. According to Microsoft, it only allows for very short bursts of work, which should reduce the window for any unnecessary processes to initiate, but that's not a guarantee. Windows maintenance tasks are still run in this mode, and other tasks can take advantage of the hardware being active to start up additional processes.

Before Modern Standby, laptops mostly relied on what's known as the S3 power state ("traditional sleep", as Microsoft calls it), and this was much more aggressive in reducing power. This saved the current state of system memory and shut down the CPU and potentially other motherboard components to save power. This meant it would take a little longer for a computer to wake up, but power consumption in sleep mode was truly minimal, which meant that it was extremely unlikely the computer would lose enough battery to die while it wasn't being used.

Laptops also used to include a Hibernate feature (also known as the S4 power state), which would go even further and shut down system memory as well, instead writing its current state to the memory page file on your disk. This resulted in a much slower wake-up process, but it also yielded the best battery savings and essentially guaranteed you'd be able to pick up where you left off. However, this feature has been disabled on most modern devices.

What can you do?

Be more wary

With this in mind, you may be wondering what you can do to prevent losing work while your computer is in sleep mode. Perhaps unsurprisingly, the easiest solution may be to be more mindful of when you close your laptop abruptly and you might have unsaved work. Whether you're shutting it down or putting it to sleep, it's always a good idea to save your work before you leave your computer unattended. The battery could die, something could crash when you wake it up, and so on. It's always best to be on the safe side.

But if you do want to keep using sleep mode more liberally and you're often in situations where you end up putting the computer to sleep, there are some things you can try. You can use the powercfg /a command in Windows Terminal to see if the S3 sleep state is available for your PC, and then you can modify your registry to disable Modern Standby, which will force your PC to switch to the S3 sleep mode. You'll want to avoid disabling Modern Standby (S0) if your computer doesn't show S3 sleep as supported. Doing this may make it so your laptop turns off completely when you close the lid, which would make you lose your work anyway.

Alternatively, you can also try to enable the hibernate option on your PC. This tends to be more widely supported, though it requires you to actively choose to hibernate instead of just closing your laptop.

Don't trust Windows

Whether you decide to start saving your work more often or you end up enabling more traditional sleep modes, what matters most is that you're careful about trusting Windows to keep your work safe. There are lots of ways things can go wrong, and with the default approach Windows takes to sleep mode, there's always a higher-than-desirable chance that you will, in fact, lose some work.