How to Make Windows Lock Automatically When You Walk Away

You get up to refill your coffee. Answer the door. Rescue something from the printer. Find out what the dog is barking at this time.

And your computer just sits there. Signed in, unlocked, with your email, your bank tab and whatever else you were doing on the screen.

Windows has a feature built for exactly this, and almost nobody turns it on. It’s called Dynamic lock. It uses your phone to tell when you’ve walked away, and then it locks your PC for you.

What Dynamic Lock Actually Does

Dynamic lock watches the Bluetooth signal from a phone you’ve paired with your PC. When that signal drops low enough, Windows assumes you’ve left and locks the computer. Microsoft says it locks within a minute after you’re out of Bluetooth range.

To get back in, you sign in the normal way: PIN, fingerprint, face or password.

One thing it does not do: unlock the PC when you come back. Your phone is only an “I’ve probably left” signal. It’s not a key. That’s the right design, because a PC that unlocks just because a phone is nearby would be a security hole.

Step 1: Pair Your Phone With Your PC

If your phone already shows up under Bluetooth & devices on your PC, skip to Step 2.

1. Turn on Bluetooth on your phone.
2. On the PC, open Settings → Bluetooth & devices.
3. Select Add device, then Bluetooth.
4. Pick your phone from the list.
5. Check that the same code shows on both screens, then approve the pairing on both.

That works with iPhone and Android. You don’t need Phone Link or a cable for this. Plain Bluetooth pairing is all Dynamic lock needs.

Step 2: Turn On Dynamic Lock

1. Open Settings → Accounts → Sign-in options.
2. Scroll down to Dynamic lock and expand it.
3. Check Allow Windows to automatically lock your device when you’re away.

Windows should show the name of the paired phone it’s going to watch. If it says it can’t find one, make sure Bluetooth is on for both devices and the phone is nearby, then try again.

It’s on Windows 10 too, under the same Sign-in options area. The screens just look a little different.

Step 3: Test It (Don’t Just Trust It)

Stay signed in, put your phone in your pocket, and walk far enough away to leave Bluetooth range. Another room, or out to the mailbox. Give it a minute, then come back. You should see the lock screen.

If it didn’t lock:

• Make sure you took the phone Windows is paired with, not your tablet.
• Check Bluetooth is still on for both the phone and the PC.
• Walk farther. Bluetooth can reach through walls further than you’d think.
• Restart both devices if the Bluetooth connection seems stuck.
• On a work or school PC, your IT department may have switched the feature off.

The Catches (Read These)

It’s not instant. “Within a minute” means someone could still get to an unlocked screen in that time, and if your Bluetooth signal reaches through walls, it can take longer. If something sensitive is on the screen, press Windows key + L before you stand up. That locks the PC immediately, and it’s still the habit worth building.

It tracks your phone, not you. Leave the phone on the desk and Windows has no idea you left. It stays unlocked for as long as the phone sits there.

It only locks. Coming back doesn’t sign you in. If typing a PIN every time sounds annoying, Windows Hello (fingerprint or face sign-in) makes getting back in quick without letting your phone do it for you.

So think of Dynamic lock as the seatbelt, not the brakes. It’s there for the times you forget.

Who Should Turn This On

• Anyone with a PC in a busy house (kids, roommates, a curious spouse)
• Laptop users in offices, classrooms, libraries or coffee shops
• Anyone whose screen lock timeout is set to “eventually” or “never”
• Anyone who has ever said “I was only gone a second”

It’s less useful if your phone lives on the desk next to the keyboard, or if you keep Bluetooth turned off.

(While you’re locking things down, these are worth ten minutes too: How to Harden Windows Without Going Overboard and 5 Security Checks Most People Skip.)

The Short Version

1. Pair your phone with your PC over Bluetooth.
2. Go to Settings → Accounts → Sign-in options → Dynamic lock and check the box.
3. Test it by walking away with your phone.
4. Keep pressing Windows key + L when it matters. Dynamic lock is the backup.

Windows can finally tell when you’ve left the room. It just needs your phone to file the missing-person report.

Stay grumpy.

Source: Microsoft Support: Sign-in options in Windows