Region : Model : Hardware Version : Not Clear Firmware Version : ISP : Download this It'll let you select either band I've just installed them, without the utility and now, I can select 5 ghz

Get these then you'll have 5 ghz. I've just installed the drivers (without the utility). Now I can select the 5 ghz

Its because of the drivers. It'll work in 8.1 if you use the drivers off the site. Windows or windowsupdate drivers DONT support 5 ghz They dont work in Windows 10 either. You'll only get the option...

Connect a cable and update the wireless thru its entry in device manager. See if windowsupdate can find a driver

Now that Windows 10 is out when will you make a driver for it?

Update the driver in device manager. I've got the same adapter it works fine. But I'm waiting for TPlink to make a windows 10 driver so I can connect to the 5ghz channel on the router