Windows Dynamic Lock Guide: Secure Your PC With Bluetooth Phone Pairing

MakeUseOf's Manuviraj Godara wrote about the feature this week. He calls it one of those small Windows features you "didn't know you needed," and describes how it saves him when he forgets to lock his laptop in cafés and coworking spaces. His experience was positive but not perfect, and the imperfect parts matter as much as the good ones.

What Dynamic Lock actually does​

Microsoft's documentation describes Dynamic Lock as a feature that automatically locks a Windows device when a Bluetooth paired phone signal falls below the maximum Received Signal Strength Indicator (RSSI) value. The aim is simple: it makes it more difficult for someone to gain access to your device if you step away from your PC and forget to lock it.

The feature first appeared in the Windows 10 Creators Update in 2017. MakeUseOf notes it has barely changed since, including on Windows 11. Microsoft's official page lists both Windows 10 and Windows 11 as supported.

There is a catch in Microsoft's own wording. The dynamic lock feature only locks the device if the Bluetooth signal falls and the system is idle. If the system isn't idle (for example, an intruder gets access before the Bluetooth signal falls below the limit), the device won't lock. Microsoft therefore calls it an "additional barrier," not a replacement for locking the PC yourself.

In practice, if someone sits down at your laptop and starts moving the mouse before Dynamic Lock kicks in, the feature does nothing. It covers forgetfulness. It won't stop a determined snoop.

Section summary: Dynamic Lock watches the Bluetooth signal from your paired phone and locks the PC once that signal drops, but only if the PC is also idle.

How long does it take to lock?​

Sources disagree here, so treat any number as approximate:

• MakeUseOf says locking takes about 30 seconds after the signal weakens.
• XDA Developers says that once the phone leaves Bluetooth range, Windows automatically locks itself within 30 seconds.
• Geek Rewind describes a wait of roughly thirty to sixty seconds after you step away before triggering the lock screen.
• RottenWiFi says Windows may lock within about one minute after the phone leaves range, and can act only when the computer is idle.

Microsoft's Dynamic Lock documentation doesn't promise a fixed countdown. When you'll walk away depends on Bluetooth signal behaviour, which Microsoft says varies with the environment. Assume a window of half a minute to a minute, during which your screen is fair game.

Setting it up: step by step​

Prerequisites​

• A Windows 10 or Windows 11 PC with working Bluetooth (built-in or a USB adapter)
• A smartphone with Bluetooth. MakeUseOf used an iPhone, and Geek Rewind says supported devices include most modern smartphones, such as iPhones and Android devices, as long as they pair to your computer using standard Bluetooth
• A sign-in method set up (password, PIN or Windows Hello) so a locked screen actually protects anything

Step 1: Pair your phone​

Windows 11:

1. Open Settings > Bluetooth & devices.
2. Turn the Bluetooth switch on.
3. On your phone, open its Bluetooth settings, find your PC and pair the two devices.

Windows 10:

1. Go to Settings > Devices > Bluetooth & other devices.
2. Turn Bluetooth on. Geek Rewind's Windows 10 instructions also say to click Add Bluetooth or other device to pair your phone with the PC by following on-screen instructions.

Step 2: Turn on Dynamic Lock​

1. Open Settings > Accounts > Sign-in options.
2. Find and expand the Dynamic lock section.
3. Tick the checkbox. Microsoft's current support documentation labels it "Allow Windows to lock your device automatically when you're away." Some guides show slightly different wording, so look for the checkbox under the Dynamic lock heading.

Step 3: Test it​

Mundobytes suggests this test: stand up with your phone and walk away until you are out of Bluetooth range of the PC. The system should automatically lock after about half a minute. Leave the PC idle while you test, because any input resets the clock.

What success looks like: you come back to the Windows lock screen and have to sign in again. Your apps will be where you left them, because a lock isn't a sign-out.

When Dynamic Lock misbehaves​

MakeUseOf's results were mixed:

• iPhone 14 Pro + Surface Laptop 3: mostly smooth. There was one unexpected lock while the phone was nearby, which the writer guesses may have been caused by power-saving modes on both devices.
• Desktop with a USB Bluetooth adapter: frequent false locks. The writer blames the lack of built-in Bluetooth.

These are one writer's observations, not lab results. No official source we reviewed says USB Bluetooth adapters cause false locks. Microsoft does warn that RSSI readings are relative and depend on conditions, so the same settings can behave differently in different places. Bluetooth signal strength is a rough stand-in for distance, not a measuring tape. RottenWiFi says the same: Dynamic Lock uses the Bluetooth signal from a paired phone, not a precise distance measurement, to decide when the phone is no longer nearby.

Troubleshooting checklist​

1. It never locks. Mundobytes suggests checking that your phone is still paired, that your PC's Bluetooth hasn't been disabled to save power, and that there aren't any walls or objects blocking the signal. Also make sure nothing is keeping the PC busy, since any input stops Dynamic Lock.
2. It locks while you're sitting right there. Try turning off aggressive power-saving modes on the phone and the PC. That's the MakeUseOf writer's guess, not a confirmed fix. Desktop users with USB adapters might try a different USB port or an updated adapter driver. That is general Bluetooth troubleshooting, not a documented Dynamic Lock fix.
3. The setting won't stick or is missing. Make sure Bluetooth is on and the phone is paired. On work PCs, your IT department may control the setting through policy (see below).

It locks, but it won't unlock​

MakeUseOf's other complaint: when your phone comes back into range, Windows doesn't unlock itself. You still have to sign in. Geek Rewind confirms it: When you return, the signal strengthens, but you still need to use a PIN, password, or Windows Hello to log back in rather than having the PC unlock automatically.

From a security point of view, that's correct. If your phone could unlock your PC, anyone who took your phone and walked over to your desk would get in too.

The practical fix is Windows Hello. Set up face recognition, a fingerprint or a PIN on the same Sign-in options page, and getting back in takes a glance or a tap instead of typing a long password. The MakeUseOf writer says Windows Hello on his Surface makes Dynamic Lock painless, while PCs without Hello hardware mean typing the password every time.

For IT admins: Group Policy and Intune​

On a managed fleet, admins don't have to rely on users ticking a box. Microsoft documents two options:

• Group Policy: enable Configure dynamic lock factors under Computer Configuration > Administrative Templates > Windows Components > Windows Hello for Business.
• Intune: create a custom configuration profile (Windows 10 and later, Templates – Custom) with an OMA-URI setting at ./Device/Vendor/MSFT/PassportForWork/DynamicLock/DynamicLock set to Boolean True. A second string setting at ./Device/Vendor/MSFT/PassportForWork/DynamicLock/Plugins holds the signal rule.

Microsoft's default signal rule targets Bluetooth devices of class Phone (classOfDevice="512"), with rssiMin="-10" and rssiMaxDelta="-10". Microsoft says the default in-range value lets a user move around an average-sized office or cubicle without triggering a lock. The rssiMaxDelta value tells Windows to lock once the signal weakens by more than 10. Phone is the only supported device class for now, so a smartwatch or headset won't work as the trigger.

Microsoft also recommends keeping the default values and testing in each environment before a wide rollout. An open-plan office, a lab full of radio noise and a home office may all behave differently. If your helpdesk starts getting "my PC keeps locking" tickets, that's the first place to look.

Don't confuse it with Presence Sensing​

If your PC locks or turns off its screen when you leave and you never paired a phone, you may have Presence Sensing, a separate feature. Microsoft says it's only available on some Windows 11 PCs with a built-in presence sensor. Its settings live under Settings > System > Power & battery > Screen and sleep. Options can include turning off the screen when you leave, waking the device when you approach, and locking the device when you leave while an external display is connected. Which options appear depends on the manufacturer and, on work PCs, your organisation.

Presence Sensing uses dedicated hardware. Dynamic Lock uses the phone in your pocket. They do overlapping jobs in different ways.

Expert take: worth enabling, with realistic expectations​

Dynamic Lock costs nothing, needs no software and has almost no downside beyond the odd false lock, so you might as well turn it on. Just know what it does. It catches the times you forget. It doesn't defend against someone who's waiting for you to walk away.

A sensible setup looks like this:

1. Press Windows key + L every time you get up. Microsoft's own security guidance names this shortcut, and it locks instantly.
2. Enable Dynamic Lock for the times you forget.
3. Set an idle timeout as a final backstop. Microsoft suggests requiring sign-in when waking from sleep, and says 10 or 15 minutes of idle time is usually a reasonable interval, though you should choose what suits you.
4. Set up Windows Hello so frequent locking doesn't drive you to turn everything off.

The MakeUseOf writer uses Dynamic Lock the same way: as a backup layer for café coffee runs and unexpected phone calls, not as his main lock. For anyone who works in libraries, airports or coworking spaces, that's the right way to use it.