title: Batch check if mapped network drive exists
body: <p>I'm currently writing a script that should map a network drive to the letter <code>Z</code> , i'm using the command 
  <code>net use z: \\path</code> , the thing is that if the user is already using this letter i won't be able to map it, is there any way to check the existense of this drive (z) and if it exists to unmount it and mount it to a different letter and still use the <code>z</code> drive which i need for my script, this is a part of an installation, and it should be on Z drive.</p>