"Since it's such a frequently asked question I've documented it here with some images which should hopefully clear up any confusion. The following screenshots show how to identify the Bluetooth stack on your Pocket Pc without writing any code or delving into the registry or system files."
Microsoft MVP, Peter Foot, has written a short guide in a bid to help new Pocket PC users identify their Bluetooth stack. If you have the desire to find out more, feel free to read the guide at his personal blog.