I am using TM300 (Dell Widcomm Stack/Drivers) and following a BIOS Flash, all the Devices (50+?) went through the Windows "Found new hardware" and I let "Windows find the best" which thashed the Widcomm for MS Stack/Drivers.
This was Ok for the printer, but would not connect (the recognized and installed) GPS without wanting "Pairing" (un-available on my Holux GPS).
Jon's Guides - Bluetooth - Introduction
Jon wants you to start at the above page and solution was found
{HERE}
Unlike Jon's advice (or Microsofts below), I did not remove any Drivers but just went through to step #7 and then directed (Browsed) the Install Wizard to the location of the Dell Widcomm Driver that I had just installed (and could not find Bluetooth). Three weeks now and the Windows Stack has not done anything with Bluetooth.
All my Bluetooth Devices are working great (including a new Microsoft Bluetooth IntelliMouse that was plug'n'play and uses the ALPS Drivers, no extra drivers for it installed.
Remove MS Stack