I just recently got an Intel 7260hmwdtx1 802.11AC desktop PCIe adapter from Amazon - nice product, and I get great speeds with Wifi on Windows 8.1!
However, the Bluetooth part of it is giving me a headache getting it to work with my Intel DQ77MK motherboard.
I've downloaded the following drivers and installed them from here:
1) Intel Proset wireless bluetooth software 3.1.1309 for Windows 8.1 (64 bit, which I have)
2) Intel Proset wireless software for WIndows 8.1, v 16.5.3 (64 bit, which I have)
I have the card installed in the 1X PCI-e slot on the Intel DQ77MK motherboard. I've tried hooking up the bluetooth wire from the card to all four of the internal USB 2.0 headers on the DQ77MK. However, I keep getting an "Unknown USB Device (Device Descriptor Request Failed)" error for the associated USB/Bluetooth device on any of the ports. I can plug other things (like a card reader with the same 5-pin style plug) into those ports, and they work fine, so I know it's not the ports on the DQ77MK.
Is there any other trick to getting the Bluetooth on here working properly?
Thanks for posting the screenshot; we will follow up in the previously existing thread here: https://communities.intel.com/thread/45971. Please make sure you have the Intel® Chipset (INF) driver installed for the motherboard and let us know there if the issue persists.