That's not a surprise - the pads aren't Bluetooth, they're RF.
You can get the wireless pads recognised on a PC if you use the play and charge kit cable but it Windows detects it as an unknown USB device and the MS drives don't install.
I have read of problems in some games with the wired pad and MS drivers and have heard of better success with the XBCD drivers. Can't say I've had any issues with the MS drivers personally so I've stuck with them.