Introduction: Bluetooth Proximity PC Lock

Have you ever been called away from your laptop in such a rush that CTRL-ALT-DEL was just asking too much? And I wager, you never go anywhere without your phone, even the bathroom. Am I right? Phones have become such a part of society they are almost considered a fashion accessory.

If there was only way to make these two seemingly independent concepts work together.

Well, there is!!!!

This instructable documents how you can use the Bluetooth feature of your cell phone as an automatic proximity locking device for your Bluetooth enabled laptop.

Step 1: "What Do I Need?" You Ask

That is simple. You just need:

1-a Bluetooth enabled cell phone

2-a Bluetooth enabled laptop

3-BtProx program.

"But wait, I don't have a Bluetooth enabled laptop!" You say.

Well, just pick up a USB Bluetooth dongle, follow the instructions for installing that, and now you have a Bluetooth enabled laptop. Sorry, I don't plan to cover that step here, as it is not the purpose of this instructable.

Step 2: BtProx? What and Where?

BtProx is a free downloadable program that installs the proximity program. It can be downloaded from

After downloading the executable, run the install program. It will place an icon on the desktop as well as in the system tray.

Step 3: Phone Meet Laptop - Laptop Meet Phone

Now you have to pair the two devices. Activate the Bluetooth setting on your phone and set to visible mode. This is how your laptop will find it.

On your laptop, down on the system tray, look for the Bluetooth icon. Right click and select Add a Bluetooth Device. This will open the Bluetooth pairing screen. At that point your laptop will see your phone.

On the laptop, click the pair button under your phone's name. This will launch the pairing process.

After this, your laptop will sync the appropriate signal with your phone.

When this is done, your phone will be listed as connected in the listed of Bluetooth devices and on the phone your laptop will be listed as connected in the list of Bluetooth devices.

Step 4: Launch BtProx

On the desktop of the laptop, open the BtProx program.

Click the ... box listed for "Used Device." This will display the list of paired Bluetooth devices. Select your phone.

Under that is the Timeout settings. This is in minutes. If you set it to 0, it will lock within 15 seconds of loosing Bluetooth connectivity with your phone.

Click on Start.

In the system tray, the BtProx icon will state that your device is in range.

Hide the BtProx program.

Step 5: Just Walk Away

That is all! Just walk away. Granted it will be hard to see if it works unless you leave your device in a whole different area for a minute while your laptop searches for the Bluetooth connection. When it cannot find the Bluetooth signal from your phone, it will display the locking count down. My laptop made a dinging countdown so I could tell when it was preparing to lock.

Keep in mind that different devices have different Bluetooth ranges, so I am not sure just how far away your phone has to be before your laptop can no longer see it, but some trial and error, you will find that signal threshold.

I hope you liked this and find it useful. And hey, vote for it in the contest, too, please.

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