I have intel 7265 dual band AC wifi card with builtin bluetooth. Some days ago windows came up with an error unknown USB (I went in event manager to see what happened). And now the bluetooth is not available. I tried troubleshooting it. But windows is not finding any bluetooth device attached. In device manager i can see unknown USB device. When I turn off bluetooth from wireless option in bios this unknown USB disappear in device manager. Also in bios system information, under bluetooth there is none as device. I already installed latest drivers with support assist. I also tried drivers from intel.