About 90% of bluetooth dongos will work with the bluetooth stack that comes with SP2 however for the other 10% lets read below :
Lets say you just bought a new bluetooh dongo for your computer/laptop and want to use the built in XP SP2's bluetooth stack instead of the stack that came from the manufacture but no matter what the Microsoft stack does not work. Here is what you do to solve this problem
Goto Device Management ( usually I right click on the My Computer icon on the desktop and click on Manage ) then look under the device list and you will see that XXXX BLUETOOTH ADAPTER has the yellow question icon on it. Double click on that icon and goto the Details tab and collect the string listed in the big window
For mine it was a newer Belkin Bluetooth USB Adapter CL2 with the ID of USBVID_050D&PID_01316&2102307&0&1
From googling I quickly found that VID_050D&PID_0131 is not part of the id's listed for the microsoft's native stack prob due to the fact that this is a fairly recently released device and although the native stack supports Belkin bluetooth usb devices the ID of this device was not listed.
unplug the USB device
find the file called bth.in_ (usually stored in WINXPSP2 CD:I386BTH.IN_ )
copy the file to a temp directory on the local hard drive and use alzip or winzip to uncompress it
Edit it and include the ID
Belkin Bluetooth Adapter= BthUsb, USBVid_050d&Pid_0081
Belkin Bluetooth Adapter= BthUsb, USBVid_050d&Pid_0084
Belkin Bluetooth Adapter= BthUsb, USBVid_050d&Pid_0131 <-- this line
Update the driver for the Belkin Bluetooth Adaptor using the manual steps and point the HAVE DISK to the directory where the BTH.INF is located. It will find rest of the files automatically.