Windows Dynamic Lock: set it up and test its limits

Leave an unlocked PC to grab something from another room and it can remain open to whoever is nearby. Windows Dynamic Lock adds a fallback: pair a phone over Bluetooth and Windows can lock the PC when the phone's signal drops below a threshold while the computer is idle. It is useful when you forget, but it is not a precise distance sensor or an instant lock. Lock the PC yourself when you step away; let Dynamic Lock catch the occasional miss.

Microsoft documents Dynamic Lock for Windows 10 and Windows 11. The reliable way to decide whether it suits your setup is to enable it, then test it with your own phone and PC. Bluetooth signal strength varies by environment, and Microsoft says the computer must be idle before the feature locks it.

Pair your phone and turn on Dynamic Lock

You need a Windows PC with Bluetooth and a phone that can pair with it. Keep Bluetooth switched on for both devices.

1. Pair the phone with the PC. Open Bluetooth settings in Windows and add the phone as a Bluetooth device. On Windows 11, open Settings → Bluetooth & devices. On Windows 10, open Settings → Devices → Bluetooth & other devices. Follow the pairing prompts on both screens.
2. Open Sign-in options. In Windows, go to Settings → Accounts → Sign-in options.
3. Turn on Dynamic lock. Find Dynamic lock and enable the option that allows Windows to lock the device automatically when you are away.

Microsoft's original Dynamic Lock instructions also require pairing a phone over Bluetooth and enabling the feature from Sign-in options. If you cannot find the setting, search Settings for Sign-in options. On a work or school PC, the option may be controlled by your organisation; ask IT before changing device policies.

Test it somewhere safe

Save your work first. Try the check at home or in another place where nobody else can reach the PC while you step away.

1. Leave the PC signed in and idle, with the paired phone on you.
2. Walk far enough away for the phone's Bluetooth signal to drop, and give Windows time to respond.
3. Check that the PC reaches its lock screen. When you return, sign in with your usual method.

Microsoft's first announcement described a 30-second delay in an early Windows Insider build. Treat that as a historical reference, not a timing guarantee for every Windows version, phone or Bluetooth adapter. Its later documentation describes the signal threshold and idle-state requirement rather than one universal distance or countdown. The useful result is what your own PC does in the place where you normally use it.

What Dynamic Lock can and cannot tell

Dynamic Lock follows the paired phone's Bluetooth signal, not your body or location. If you leave your phone beside the computer, Windows has no signal that you have gone. If the signal weakens while you are still nearby, the PC may lock sooner than you expect. Microsoft notes that Bluetooth signal measurements vary with the environment, so the same settings can behave differently in different spaces.

There is another limit: the PC must be idle when the signal falls. Microsoft describes Dynamic Lock as an additional barrier and says it does not replace locking the computer yourself. For an immediate lock, use Windows' manual Lock action before leaving. Dynamic Lock is for the moment you forget, not a reason to rely on Bluetooth as your only safeguard.

If it does not behave as expected

• The PC does not lock: check that Bluetooth is on, the phone is paired with this PC, Dynamic Lock is enabled, and the PC is idle. Repeat the test with the phone on you rather than left on the desk.
• The PC locks while you are still nearby: Bluetooth proximity is approximate. Repeat the check in your usual space and note where the signal changes; do not treat it as a fixed room boundary.
• The setting is unavailable on a managed PC: stop there and contact IT. Microsoft documents administrative controls for Dynamic Lock, so a work policy may govern the setting.

Returning with your phone does not substitute for signing in. The feature locks the PC when its conditions are met; you still use your normal sign-in method to resume work. Keep the manual Lock action as your dependable habit, and treat Dynamic Lock as a useful backup.

Sources

• Microsoft Learn, Dynamic lock (last updated 2 December 2024).
• Microsoft Windows Insider Blog, Announcing Windows 10 Insider Preview Build 15031 for PC (8 February 2017). The 30-second timing above refers to this preview build.