This will only work on PocketPCs and Smartphones that use the Microsoft BlueTooth software. Unfortunately, many PocketPC vendors and one Smartphone one have decided to use different Bluetooth software that doesnt let developers write programs for it. If you have a device with that software, this program isnt going to work. Theres no easy way to tell which BTh software you have. Your best bet is to just run the program and see if it works. This code also uses .net, so your device needs to be running Windows Mobile 2003 or later.