title: adb.exe has stopped working, Nexus 7 not detected over USB
body: <p>I'm using Google Nexus 7 to debug an applications. but now it is prompting the error message below and and popup is coming stating that the USB device is not recognized.
  But it was working properly a few days back. </p>
  
  <p>I have not made any updates on the device or the Android SDK.</p>
  
  <p>adb stopped:</p>
  
  <p><img src="https://i.stack.imgur.com/dK4PP.jpg" alt="enter image description here"></p>
  
  <p>USB device not recognized:</p>
  
  <p><img src="https://i.stack.imgur.com/0FLAz.jpg" alt="enter image description here"></p>
  
  <p>What's wrong?</p>