Android device is not connected to USB for debugging (Android studio)

Question

I am trying to debug my application using a real device instead on the emulator. When I try to connect, it gives me the message:

USB device not found<

Answer 1

I had this problem with a Nexus 7 - it appeared in Device Manager fine but wasn't recognised by Android Studio. The device had USB debugging turned on. Eventually I noticed an icon in the top left hand corner that said "Connected as a media device. Touch for other USB options." When I selected this I was able to change from Media Device (MTP) to Camera (PTP) and then it started working.