1. Go to BlueSoleil web site http://www.bluesoleil.com/products/S0001201008080001.html
2. Register yourself it you did not yet
3. Download 9.X version (Do not download 10.X version which is retail only version)
4. The UD100 is already licensed for BlueSoleil driver so you do not need to enter any license key. If you the driver is asking you to enter the license number, please make sure you are using 9.X version and the UD100 is the only Bluetooth device on your computer.