title: How do I force Robocopy to overwrite files?
body: <p>In general, Robocopy ignores files for which lastwrittendate and filesize are the same. How can we escape this design? I'd like to force overwriting with Robocopy.</p>
  
  <p>I expected that dst\sample.txt should be written test001.
  But these file are recognized as the same files by Robocopy and not overwritten. The "/IS" option is not effective in this case.</p>
  
  <pre><code>New-Item src -itemType Directory
  New-Item dst -itemType Directory
  New-Item src\sample.txt -itemType File -Value "test001"
  New-Item dst\sample.txt -itemType File -Value "test002"
  Set-ItemProperty src\sample.txt -Name LastWriteTime -Value "2016/1/1 15:00:00"
  Set-ItemProperty dst\sample.txt -Name LastWriteTime -Value "2016/1/1 15:00:00"
  
  ROBOCOPY.exe src dst /COPYALL /MIR
  Get-Content src\sample.txt, dst\sample.txt
  &gt; test001
  &gt; test002
  
  ROBOCOPY.exe src dst /COPYALL /MIR /IS
  Get-Content src\sample.txt, dst\sample.txt
  &gt; test001
  &gt; test002
  </code></pre>