title: WMI Query to determine DNS Servers without null entries
body: <p>I can use the following WMI query to determine any DNS servers my machine might be using:</p>
  
  <pre><code>SELECT DNSServerSearchOrder
  FROM Win32_NetworkAdapterConfiguration
  </code></pre>
  
  <p>However, the following query I wrote to ignore null entries is invalid and I don't know why:</p>
  
  <pre><code>SELECT DNSServerSearchOrder
  FROM Win32_NetworkAdapterConfiguration
  WHERE DNSServerSearchOrder!=null
  </code></pre>
  
  <p>Is there a way to filter out the null entries?</p>