title: Why does the assoc command in cmd doesn't change the program that opens a file with the specified extension?
body: <p>I have tried a lot, but the assoc command doesn't work for me. 
  When I type </p>
  
  <pre><code>assoc .html=txtfile
  </code></pre>
  
  <p>the command seems to have been executed as expected. When I check the extension and the associations the .html association has changed to txtfile. But normally it should mean, that the .html files are opened with notepad from now, shouldn't it? Because that is not the case!
  I also tried to restart my PC after that.
  What have I done wrong?</p>