title: Put Md5 checksum to file name
body: <p>There some files in directory 1.txt 2.txt 3.txt .. n.txt , i need rename them all with their md5 sum. 
  I tired </p>
  
  <pre><code>for %f in (*.txt) do certutil -hashfile "%f" MD5 | findstr /C:2
  </code></pre>