There are many kinds of Bluetooth devices and these steps are only relevant to some. Consult the user manual for the device or the manufacturer website for specific instructions. For example, the steps to pair a Bluetooth surround sound system to a laptop are not the same as pairing headphones, which isn’t the same as pairing a smartphone.
Activate the Bluetooth function on the mobile device to make it discoverable or visible. If the device has a screen, look for Bluetooth in the Settings menu. Other devices have a special button.
On the computer, access the Bluetooth settings and choose to make a new connection or set up a new device. For example, on Windows, either right-click the Bluetooth icon in the notification area or go to the Control Panel to find the Hardware and Sound > Devices and Printers page.