Q: I deployed servers from an image but forgot to run sysprep with the generalize switch on the source image. Do I need to redeploy all the servers I created from the image, or can I just sysprep the deployed machines?

A: The usual process when deploying from a source image is to prepare a source machine. Then you run the sysprep command with various switches, including the generalize switch.

The generalize switch performs various changes to the machine to prepare it for duplication, such as wiping the machine SID, but other sysprep providers are also called to perform other cleanup pre-duplication. Without the sysprep -generalize, all deployed machines from the image will have the same SID, which can cause problems.

The only supported method to remedy the problem is to create a new source image that has been sysprep'd correctly with the generalize switch. You shouldn't run sysprep with generalize on a deployed server. Many applications you have installed might not support sysprep, and Microsoft doesn't support machines that have been sysprep'd post deployment (see "The Microsoft policy for disk duplication of Windows installations").

Below is the typical sysprep command to use on your source machine that will be duplicated. Depending on your requirements, you can customize it with unattended answer files:

sysprep /oobe /generalize /shutdown

To see more FAQs, please go to John Savill's FAQs page on Windows IT Pro.