newbie cannot connect phone to android studio

Just installed android studio on windows 8.1.
Then I connected a phone to the PC and turn on developer debug option.
No device is listed next to the app drop down. I enter troubleshoot device connection and click rescan device. It list a bunch of USB devices including the phone under the heading "found 19 usb devices not recognized as android devices".
I tried 3 different phones:
hwawei G620, oneplus one, oneplus 5T
They all result in the same scenerio -- appear in the non android devices list. All these devices have been able to transfer files to/from the PC before turning on the debug option.
What should I try next?

 

I installed android studio on a laptop running win10 and it connects and runs the test app on the huawei without a hitch, but I still want to make it work on my desktop PC running win8.1

So the problem is not with the phone or the usb cable. No idea what to do next.