W
Lumia icon here
I also had this issue after a hard reset. I had to roll back to 8.1 to get functionality back then re upgrade to 10. I did not hard reset afterwards.
Wdrt did not detect my icon tried the power and down button combo phone still did not detect.
Tried the power button down button again. After phone vibrated I pressed the power button twice. Phone detected and downloaded 8.1 I had to repeat this process to flash the phone as well..
Did not hard reset after upgrade to 10 everything works with Usb as it should.
Hope this helps and luck to you..