DBT-120 rev3 not working

Welcome to Apple Discussions.

Here's the thing: once the Apple firmware update has been applied, your D-Link DBT-120 cannot be used with a Windows PC. This is actually a shortcoming of Windows, and not some bizarre plot by Apple to prohibit you from using the device in that environment.

The BT dongle itself does not need a key - the key is required between the device you are trying to pair and the computer (or other device).

For example, if you want to pair up a headset with a computer, you'd have to pair the headset using a key given by the manufacturer (such as 0000, or 1234). You'd punch in this code in the computer and the two should pair.

Look in the device's manual for the default access key. What are you trying to pair with your Windows PC?

No, he means the license code of the Widcomm software.

Either try the CD-ROM which came with the D-Link and have a search on it for a license file or better use the internal Bluetooth software stack of Windows XP Service Pack 2.

With Service Pack 2, DBT-120 drivers that come on the CD will not work. They will consistantly give you "license errors" and will not let any device pair with the computer. To fix this, go to D-Link's support site and follow their instructions for installing it with SP2. This will include taking off the old drivers, downloading a new set, and finally applying those which will work with the new Service Pack, after which you will disable the MS Bluetooth stack (which does not, afaik, support headsets).

I have a B4, but I don't think it should be any different for a B3.