Windows 2008 SysPrep Error [Applying System Settings]

You kick off the clone, apply the customization file (leveraging vCenter’s excellent SysPrep integration), wait a couple of minutes and pop into the console expecting to begin application installations and find this :

“Window could not parse or process the unattend answer file for pass [specialize].  The settings specified in the answer file cannot be applied.  The error was detected while processing settings for component [Microsoft-Windows-Shell-Setup].”

Pressing OK results in another endless SysPrep reboot loop.

After a bit of troubleshooting, this error condition was resolved by applying a valid Windows Key in the customization wizard.  Apparently a more informative (read: useful) message such as ‘Invalid Windows Key’ was too much for this dialog box to handle.

Side Note: If you aren’t using vCenter’s SysPrep integration features when cloning machines, Why Not?