I have Windows 7 64-bit running on a MacBook Pro in a Boot Camp partition. I am trying to pair with my Bluetooth Mighty Mouse and Apple wireless keyboard under Windows, but whenever I try to do so, here's what happens:

1. While on the Add a device window, I turn on the mouse or press a key on the keyboard, and the mouse or keyboard shows up in the list of available devices.
2. I click the device and then the Next button, and the window displays Connecting to device...
3. Time passes.
4. Eventually, I get this error message:

Adding this device to this computer failed

Adding the device failed resulting in an unknown error. The reported error code is 0x80070015.

Contact your device manufacturer for assistance.

I've run Windows Update and Apple Software Update. I've also tried reinstalling the drivers from the Snow Leopard DVD.

The mouse and keyboard both work fine when I boot into Mac OS X.

FWIW, after many, many repeated tries, I eventually got it to work. I don't know why. So while my problem is solved, I'd still like to get an "answer" as to why trial-and-error seems to be the only approach.

The keyboard, in particular, was hard to get set up. A few times, Windows would apparently recognize it and prompt me to enter the pairing code, but then it would time out after a couple of seconds (not long enough to enter the code). Grrrr.