Adjust Dynamic Lock Bluetooth Signal Threshold

Dynamic Lock is a Windows security feature that automatically locks your computer when your paired Bluetooth device, such as a smartphone, moves out of range. This guide explains how to fine-tune the sensitivity of this feature by adjusting the Bluetooth signal drop threshold in the Windows Registry (Regedit), allowing you to control how close or far your device must be before Windows initiates a lock.

Step 1: Open the Registry Editor

1. Press Win + R on your keyboard to open the Run dialog box.
2. Type regedit and press Enter (or click OK).
3. If prompted by User Account Control (UAC), click Yes to grant administrative permissions.

Step 2: Navigate to the NaAuth Registry Key

In the Registry Editor, use the left-hand navigation pane to browse to the following directory:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\NaAuth

Note: If the NaAuth key does not exist under CurrentVersion, right-click on CurrentVersion, select New > Key, and name it NaAuth.

Step 3: Create or Modify the Signal Threshold Value

1. Click on the NaAuth folder in the left pane to select it.
2. In the right pane, look for a value named BluetoothUserProximitySignalThreshold.
3. If the value does not exist:
   • Right-click any empty space in the right pane.
   • Select New > DWORD (32-bit) Value.
   • Name the new value BluetoothUserProximitySignalThreshold.
4. Double-click BluetoothUserProximitySignalThreshold to open its properties.

Step 4: Set the Proximity Threshold Value

1. Under the Base section, select the Decimal radio button.
2. Enter your desired threshold in the Value data field:
   • The value represents the signal attenuation in decibels (dB).
   • Higher values (e.g., 15 to 25) allow a weaker signal, meaning you can walk farther away before the system locks.
   • Lower values (e.g., 5 to 9) require a stronger signal, causing the PC to lock when you are closer.
   • The default baseline used by Windows is typically around 10.
3. Click OK to save the changes.

Step 5: (Optional) Adjust the Signal Interval and Inactivity Timeout

To further refine how quickly Dynamic Lock reacts, you can add two additional DWORD (32-bit) Values in the same NaAuth key:

• BluetoothUserProximityInterval: Controls how frequently (in milliseconds) Windows checks the Bluetooth signal. (e.g., 2000 for 2 seconds).
• BluetoothUserProximityTimeout: Controls the delay (in milliseconds) before the computer locks after the signal falls below your threshold.

Step 6: Apply the Changes

1. Close the Registry Editor.
2. Restart your computer to ensure the new Bluetooth proximity parameters take effect.