Here's Help page:
To change Bluetooth settings for your computer
Open Bluetooth Devices in Control Panel.
To allow other Bluetooth devices to find your computer, on the Options tab, select the Turn discovery on check box.
To help protect the security of your data, we recommend that you turn on discovery only when you want a Bluetooth device to find your computer.
To allow other Bluetooth devices to connect to your computer, select the Allow Bluetooth devices to connect to this computer check box.
To be notified when a Bluetooth device wants to connect to your computer, select the Alert me when a new Bluetooth device wants to connect check box.
Note
To open Bluetooth Devices, click Start, click Control Panel, and then double-click Bluetooth Devices.
Some programs can also make your device discoverable.