It is not uncommon for system administrators to clone virtual servers or take an image of physical servers running Windows Server 2008 these days. There are plenty of tools to do that these days (Ghost, Acronis, Platespin for P2V conversions, etc.) If this is something you do regularly then you won’t be unfamiliar with Sysprep or NewSID, but according to Mark Russinovich at Microsoft, the SID doesn’t matter and Sysinternals have now retired NewSID (written by Mark). NewSID isn’t supported in Windows Server 2008 and the only option now is to use Sysprep. Whilst the facts presented on Mark’s blog are correct, I have personally seen many issues cloning or imaging Windows Server 2008 machines that haven’t been cloned with Sysprep first. Let me present a typical scenario that would cause problems here.
Prior to VMware ESX 4 (vSphere) it was not possible to clone a running virtual machine to another datacenter, or to a virtual machine data store that wasn’t available on the source host. Now with VMware vSphere it is possible to clone a running virtual machine to another datacenter, even if the destination data store is not presented to the source host.