title: Powershell Get all Optical Drive Letters
body: <p>I am trying to get all drive letters of a Windows system with Powershell, but I cannot figure it out. 
  Any Ideas? </p>
  
  <p>I have tried to use <code>Get-Volume</code>, but it has no parameter for <code>-ByDriveType</code> or <code>-ByType</code> or <code>-Type</code> or anything.</p>