I discovered a very useful little help page somewhere long ago, then lost it again. It was to do with installing WIDCOMM drivers for the USB BT dongle (mine's an ePox dongle.) Anyway, I found essentially the same document written by someone over at:
I thought I would repost it here, as long as they don't mind, and hopefully it will stay available for all perpetuity...
This is a small guide for those who installed the Service Pack 2 for Windows XP and are experiencing problems with the WIDCOMM Bluetooth software..If you install the WIDCOMM BTW 22.214.171.124 Bluetooth software on Windows XP SP2, you will get the following error as soon as you double click on the blue-red system tray icon:"Your Bluetooth Software license does not include use with this Bluetooth Device"After that you will be asked to point to a valid license.dat file. However if you select the license.dat that came with your manufacturer's driver (be it on CD-ROM or downloaded from the manufacturer's website) it still won't work.The reason for this problem:In the Service Pack 2, Microsoft included a generic Bluetooth driver, naturally being WHQL-certified -- it's directly from Microsoft. The WIDCOMM Bluetooth driver however is not WHQL-certified, so Windows XP continues using the generic driver. This interferes with the WIDCOMM Bluetooth software resulting in the above error.To force Windows XP to use the WIDCOMM driver, perform the following steps:Don't plug in the Bluetooth device yet.If you have any Bluetooth software apart from the included Windows drivers installed, deinstall them and reboot. I am not sure if this is necessary, but just in case.Install the WIDCOMM BTW 126.96.36.199 Bluetooth software. When it asks you to plug in the Bluetooth device and click OK, don't, and click cancel instead.When the WIDCOMM setup has finished, plug in your Bluetooth device and let Windows install the driver. (There should be two Bluetooth icons in the system tray; one blue-white: this is the Windows driver - and one blue-red: this is the WIDCOMM driver which is deactivated.)Now go to the Device Manager, right click on the "Generic Bluetooth Radio" and select "updatedriver". Don't let Windows XP connect to the internet, then select "Choose software from a list or specified location". In the next window, select "Don't search, but select the driver to install".In the next window, activate "Show compatible hardware" (if it isn't activated already) and select your manufacturer's driver instead of the "Generic Bluetooth Radio" driver.Click next until the new driver is installed. Now the WIDCOMM system tray icon should be blue-white as well, activated and ready to use.If you now double click on "My Bluetooth Places" (e.g. on the desktop), the WIDCOMM software installation will be continued and finished.This should solve any compatibility issues with the WIDCOMM BTW 188.8.131.52 Bluetooth software and Microsoft Windows XP SP2.If you still experience problems, please reply to this thread. If necessary, I will update this HowTo accordingly.