You keep leaving your desk with your email still on screen. Somebody suggested Dynamic Lock, which locks the PC when your phone goes out of range. It sounds ideal.
It is a real feature and it does work. I want to set your expectations before you rely on it, because Microsoft's own description is more modest than the articles about it.
So this page does the reliable thing first. Dynamic Lock comes after, as the extra on top.
That order matters. It is the opposite of how this usually gets written up.
Start with the one that always works
A screen timeout plus a sign-in requirement. Unglamorous. It depends on no radio, no phone and no battery.
Go to Settings, System, Power & battery, then Screen and sleep. Set the screen to turn off after a few minutes. Three is a good number.
Then go to Settings, Accounts, Sign-in options, and find If you've been away, when should Windows require you to sign in again? Set it to When PC wakes up from sleep.
⭐ Both halves are needed. People do one. A screen that switches off without a sign-in requirement is a dark screen, not a locked computer.
Ours, and marked as ours: three minutes is the number worth choosing. Long enough that it does not blank while you read, short enough that walking to the kitchen covers it.
And learn the two-key version
The fastest lock is the one you do on purpose.
Press Windows key + L. The machine locks immediately. Nothing closes, and everything is where you left it when you sign back in.
⭐ Nothing here beats that habit. Every automatic option exists to catch the times you forget.
Dynamic Lock, and what it actually is
Now the feature you came for. Described the way Microsoft describes it.
It pairs your phone to the PC over Bluetooth and locks the machine when the phone moves out of range. Walk away with the phone and Windows locks itself.
Documented by Microsoft on its dynamic lock page: the feature locks the device when a paired phone's Bluetooth signal falls below a set strength, and only if the signal falls and the system is idle.
⚠️ Read that second condition again. If the machine is not idle it will not lock, however far away your phone is.
Microsoft also states the timing: Windows locks within about a minute after you are out of Bluetooth range.
Microsoft's own caveat, which nobody quotes
One sentence decided the order of this page.
In Microsoft's words: the dynamic lock feature "is an additional barrier. It doesn't replace the need for the user to lock the computer. It only reduces the probability of someone gaining access if the user forgets to lock it."
⭐ That is the vendor telling you not to rely on it, in the middle of its own documentation for it.
So treat it as a safety net under the habit. It is not the thing keeping your machine private.
Setting it up
Two steps. The first one is where it usually goes wrong.
Pair the phone first. Go to Settings, Bluetooth & devices, Add device, Bluetooth, and pair your phone properly. It must show as paired, not merely as seen.
Then switch it on. Go to Settings, Accounts, Sign-in options, find Dynamic lock, and tick Allow Windows to automatically lock your device when you're away.
⛔ The tick box is grayed out until a phone is paired. That is the single commonest reason people conclude the feature is missing from their machine.
If Bluetooth itself is nowhere to be found, that has three levels and a fix two owners confirmed before you get anywhere near this setting.
Test it by walking away, not by turning Bluetooth off on the phone. Range is what it measures. A switched-off radio behaves differently from a distant one.
Why it needs Bluetooth at all
The question comes up constantly, and the answer explains the limits.
Bluetooth is the only thing here measuring distance. Windows watches the signal from the paired phone and reads a weakening one as you leaving.
That is also why the feature is vague about range. Signal strength depends on walls, on a pocket against a desk, and on which Bluetooth radio your PC has.
⚠️ So there is no distance setting and there cannot be a reliable one. Anything promising a precise range is describing something Windows does not offer.
When the checkbox is grayed out and a phone is paired
Now the part I would rather you heard from me, because it is a real dead end.
Reported by an owner on Microsoft's board: the Dynamic Lock setting was grayed out and could not be changed, with no matching entry in the Group Policy Editor either.
A Windows adviser suggested unpairing the phone and reinstalling the Bluetooth driver. The owner came back the same day: "Thank you Arif, but unpairing and reinstalling did not solve the problem."
A second suggestion was a registry value, `EnableGoodbye` under the Winlogon key, set to 1 to enable. The owner replied that it "was on 1, changed it to 0, but no success, option still grayed out".
⛔ Sixteen answers. No confirmed fix.
⭐ So if yours is grayed out with a phone properly paired, stop. Do the screen timeout route at the top of this page instead, which achieves the actual goal and does not depend on any of this.
What to do on a shared or work machine
Different situation. The answer changes.
If an employer manages your PC, Dynamic Lock and the sign-in timings may be set by policy. Grayed out then means locked down, not broken.
The Windows key and L habit still works. No policy takes it away.
If you are on a local account rather than a Microsoft one, that changes your sign-in options and is worth understanding first.
Ours, and marked as ours: on a work machine, a grayed-out setting is usually a decision somebody made rather than a bug. Ask whoever manages it before you go near the registry.
The one thing worth checking afterwards
A lock that unlocks too easily is not a lock.
Look at how you sign back in. A PIN, a fingerprint or a face all work. A machine with no password at all cannot be locked in any meaningful sense, and Windows will not stop you running it that way.
Never set a sign-in method? Settings, Accounts, Sign-in options is where that starts. It is worth ten minutes before any of the automation above means anything.
Status: checked 23 August 2026. Microsoft documents Dynamic Lock as requiring a paired Bluetooth phone, acting only when the system is idle, locking within about a minute of going out of range, and being an additional barrier that does not replace locking the computer yourself. The grayed-out case has no confirmed fix on the thread read and this page says so.
How do I make my PC lock automatically when I walk away?
Set a short screen timeout under Settings, System, Power and battery, then set Windows to require sign-in on wake under Settings, Accounts, Sign-in options. Both halves are needed. Dynamic Lock with a paired phone is an extra layer on top of that, not a replacement for it.
Is Dynamic Lock actually secure?
Microsoft describes it as an additional barrier that does not replace the need to lock the computer yourself, and says it only reduces the probability of someone gaining access if you forget. It also only acts when the system is idle, so it is a safety net rather than a lock.
Why is Dynamic Lock grayed out?
Almost always because no phone is paired over Bluetooth yet, which is the fix. Where a phone is properly paired and it stays grayed out, one thread on Microsoft's own board ran to sixteen answers without a confirmed fix, so the screen timeout route is the practical answer.
How long does Dynamic Lock take to lock the PC?
About a minute after your phone is out of Bluetooth range, and only if the system is idle at the time. There is no distance setting, because the feature reads signal strength and that varies with walls, pockets and the Bluetooth radio in your PC.
The Short Version
- Screen timeout plus require sign-in on wake is the reliable pair. Most people set only one.
- Windows key and L is faster than any automation and takes nothing away.
- Dynamic Lock needs a properly paired phone. Grayed out usually means no phone paired.
- It only acts when the system is idle, and takes about a minute after you are out of range.
- Microsoft calls it an additional barrier that does not replace locking the machine yourself.
- Grayed out with a phone paired has no confirmed fix on Microsoft's own board.
- A machine with no sign-in method set cannot be locked in any useful way.
Where to Next
Set the screen timeout and the sign-in requirement now, both of them, and give it three minutes. That takes about a minute and it does the actual job whether or not Dynamic Lock ever works for you.
If Bluetooth is missing entirely rather than refusing to pair, that has its own three levels and one fix two owners confirmed.
If you are weighing a local account, switching to one has trade-offs worth reading first.
And if Dynamic Lock is grayed out on your machine with a phone paired, say below what edition of Windows you are on. That thread never got an answer and I would like to gather better evidence than it has.
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.