The reason that bluesoleil is use is because it is the only publicly available bluetooth stack that support SCO. This is the channel that carries the audio if anyone don't know much about bluetooth (not trying to offend anyone). Windows bluetooth stack is supposed to support this in Windows 7 for CSR bluetooth chipsets, but I have never been able to get it to work for me. You can easily connect to the phone with HFP with the Windows stack you just won't get any audio (which is kind of important for HandsFree/Headset). Widcomm I have no knowledge of, but I don't think it supports SCO either. It is possible to write a kernel mode driver to enable SCO, but I don't have much driver development experience. I don't think that the Windows stack would be much better with the audio either though, since it is still a software implementation, which is the why bluesoleils audio is so bad. If you could create a usb hardware solution that supports SCO in the hardware and transmits it to the computers line in port, that would be the only way to get audio that is the quality of HandsFree kits that you would install in your car. I hope that this explination helps somewhat. I have been researching bluetooth for over a year, and have come to find out that bluesoleil at this point is the only cost effective solution (really the only one unless you mod a HandsFree kit to connect to the computer) to date. Please let me know if I am wrong on this, because I would be very happy to work on a different stack. I wish that Bluez was supported on Windows. If it was, then we would be set. Bluez is an awesome stack. I have developed on it for a few projects.