WARNING: This is intended for use in a lab environment rather than production. Given the nature of domain controllers, all details here should be used with extreme caution as damage is HIGHLY POSSIBLE and data loss is a risk.
At various time I want to test something that I want to install on my production system at home without actually risking damaging anything. The easiest way I find is to make a copy of the virtual machine hard disks and start them up attached to a new LAB version of the machine, on an isolated Virtual network of course. This works fine for Domain Controllers also which makes it quicker to test things like Exchange with your actual configuration.