Can't pair BT keyboard, k810, using USB Dongle (BCM20702A0)

Hello community,

After fairly extensive research and testing, I am still unable to get my brand new Logitech K810 keyboard to pair with a windows XP (x86) desktop. It has worked with my tablet, android phone, mac (on Mavericks), windows 7, and others. I realize that the keyboard is not listed as directly supported on XP, but assumed bluetooth was a standard and should work...

My USB bluetooth dongle is using a BCM20702A0 (Broadcomm USB 2.0 BT 4.0) chipset.

What happens is, using the Widcomm stack, the Broadcomm bluetooth program will find the keyboard, show a pairing screen, and ask me to enter a 6 digit pairing code, even crossing off the numbers displayed for the pairing code as I type them on the keyboard. After all numbers are typed, and blanked out with a black circle as typed, it prompts me to hit enter, then proceeds to error out after 30 seconds - 1 minute. So close, yet so far.

In any case, I have tried adding the hardware ID of the bluetooth adapter (a "Plugable" bluetooth 4.0LE & Classic bluetooth compatible) to the bth.inf file in the windows system (INF) folder, in order to convince windows to use the native bluetooth stack, without success. The windows native stack was used, but the driver doesn't work properly. After adding this line to the file, I removed the old driver and plugged the bluetooth module back in. Then Windows installs the MS driver, however there is an error that occurs near the end of the driver install that causes the device to appear with a yellow exclamation mark in device manager, and it is not usable.

I have also tried using a freeware utility (bluetoothdriverinstaller.exe) that is supposed to automate what I did above, basically just forcing the dongle to use MS supplied drivers. This also fails.

I have also tried installing setpoint, where my keyboard also fails to show up. This isn't really surprising, since I'm not using Logitech's "Unifying receiver" (can't, the k810 doesn't support it, wouldn't want to use it anyways).

Reinstalls of Broadcomm's Widcomm driver and utility also do not help.

These exact problems have been replicated on two XP (x86) PCs, albeit using the (exact) same bluetooth USB module.

Any help would be greatly appreciated. This keyboard is for my employer's conference room PC, and I'm looking like an idiot for being unable to get something seemingly simple, bluetooth, to work...