Yesterday I was asked by an IT guy if the use of newsid.exe against a cloned Windows 2012 R2 virtual machine would work to prevent SID conflict. Well, what he didn't know, is that newsid is old history now (even the download is no more available) and that a new wonderful switch in the Sysprep utility is born to make the job of generalizing your master VM become a breeze. Let me quickly explain that.
The new switch for Sysprep is /mode:VM
This switch is available only through the command-line and causes Sysprep to skip the physical device recognition phase. This way deploying a clone of any VM becomes very rapid, since detecting changes in the installed hardware was time-consuming.
Here's the complete Sysprep syntax to use. Open an elevated command prompt, move to c:\windows\system32\sysprep, then run:
sysprep.exe /oobe /generalize /shutdown /mode:vm
and you are done. The master virtual machine will shut down and you can keep it as base host from which to deploy any other VM. Each time you start a new clone you'll be asked about your regional settings and input language, and you'll need to enter your activation key again.
Hope this helps.