title: PyUSB ValueError: No Backend available on windows 7. windows is detecting the device while pyusb is not detecting
body: <p>I have tried all possible ways but not able to get out this error.Did anyone sorted out this problem?</p>
  
  <pre><code>&gt;&gt;&gt; import usb.core
  &gt;&gt;&gt; import usb.util
  &gt;&gt;&gt; dev=usb.core.find(idVendor=0x04D8)
  </code></pre>
  
  <p>Error I'm getting is:</p>
  
  <pre><code>Traceback (most recent call last):
    File "&lt;pyshell#2&gt;", line 1, in &lt;module&gt;
      dev=usb.core.find(idVendor=0x04D8)
    File "C:\Python27\lib\site-packages\usb\core.py", line 1199, in find
      raise ValueError('No backend available')
  ValueError: No backend available
  </code></pre>
  
  <p>Before it did not show any such issue it is displaying that error recently.
  Tried including libusb0_x86.dll  in the directory C:\Python27 but still it is showing the error.Also i have installed the libusb-win32 inf wizard for the device driver. Please any python expert out here help me with this error.</p>