title: Unable to set DefaultIcon in registry
body: <p>I am attempting to update the Windows registry to add an icon for my custom file extension, and I have thus far been unsuccessful.  My current version is closest to <a href="https://stackoverflow.com/questions/8407066/how-do-i-associate-a-filetype-with-an-icon">this stackoverflow question</a>.  Unfortunately, my file's icon is still one of the generic built-in Windows icons (see screenshot below).</p>
  
  <p><a href="https://i.stack.imgur.com/AmZ2P.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/AmZ2P.png" alt="enter image description here"></a></p>
  
  <p>At this point my best guess is perhaps there is something wrong with my <code>.ICO</code> file.  I have shared it <a href="https://www.dropbox.com/s/x6owkqvm0o5152z/decrypted.ico?dl=0" rel="nofollow noreferrer">here on Dropbox</a></p>
  
  <p>Here is the full registry update I'm making with <code>regedit</code>.  As you can see, I am also associating my file extension with a <code>.bat</code> file for execution.  That works great.  Also the <em>Type</em> displayed in Windows Explorer is <em>PartQuest Archive</em> which is also great (see above screenshot).  Alas, no dice with the last entry for the icon.</p>
  
  <pre><code>Windows Registry Editor Version 5.00
  
  [HKEY_CLASSES_ROOT\pqunzip]
  @="PartQuest Archive"
  
  [HKEY_CLASSES_ROOT\pqunzip\shell]
  
  [HKEY_CLASSES_ROOT\pqunzip\shell\open]
  
  [HKEY_CLASSES_ROOT\pqunzip\shell\open\command]
  @="\"C:\\MentorGraphics\\PartQuestTools\\SDD_HOME\\common\\win32\\scripts\\pqunzip.bat\" \"%1\""
  
  [HKEY_CLASSES_ROOT\.pqz]
  @="pqunzip"
  
  [HKEY_CLASSES_ROOT\.pqz\DefaultIcon]
  @="\"C:\\MentorGraphics\\PartQuestTools\\SDD_HOME\\common\\win32\\config\\decrypted.ico\""
  </code></pre>
  
  <p>I have also attempted adding a <code>,1</code> to the end of the file name since the <code>.ICO</code> file appears it may have two icons embedded in it.  This is did not make a difference.</p>
  
  <p>For good measure, I have been rebooting after each change. I'm not certain if this is necessary.</p>
  
  <p>Any tips from the Windows experts around here will certainly be appreciated!</p>