Copy files without overwrite

Robocopy, or “Robust File Copy”, is a command-line directory replication command. It has been available as part of the Windows Resource Kit starting with Windows NT 4.0, and was introduced as a standard feature of Windows Vista, Windows 7 and Windows Server 2008.

   robocopy c:\Sourcepath c:\Destpath /E /XC /XN /XO

To elaborate (using Hydrargyrum, HailGallaxar and Andy Schmidt answers):

• /E makes Robocopy recursively copy subdirectories,
  including empty ones.
• /XC excludes existing files with
  the same timestamp, but different
  file sizes. Robocopy normally overwrites those.
• /XN excludes existing files newer
  than the copy in the destination
  directory. Robocopy normally
  overwrites those.
• /XO excludes
  existing files older
  than the copy in the destination
  directory. Robocopy normally
  overwrites those.

With the Changed, Older, and Newer classes excluded, Robocopy does exactly what the original poster wants – without needing to load a scripting environment.

References: Technet, Wikipedia
Download from: Microsoft Download Link (Link last verified on Mar 30, 2016)