title: Is DiskDrive Signature unique?
body: <p>I am currently using WMI to query various details about the underlying hardware in order to uniquely identify a machine. To this end, I came across a field called "Signature" under "Win32_DiskDrive". Is this signature unique across machines (globally)? Can this be used reliably to identify the machine? </p>
  
  <p>Thanks,
  Ananth</p>