Sysprep is a system preparation tool that allows you to edit Windows images to bring them to a generalized state. This software is present in all Windows installations, and it is very important to prepare a system for cloning and distribution on multiple machines in the same network. It is therefore an essential tool for IT administrators, especially those managing networks with Active Directory.
In fact, Microsoft operating systems have uniquely generated security identifiers (SIDs) that are assigned to each computer as part of the initial Windows configuration. Every time Windows is installed, a SID is assigned to that particular installation. If there is more than one computer with the same SID on the same network, this may cause problems.
To simplify the deployment of tens or even hundreds of workstations and servers, many IT administrators use cloning techniques from a sample operating system that is configured with the right applications, software, and configurations to distribute it to other computers using a disk image.
This is where the problem of SID duplication becomes critical. Cloning a physical or virtual computer without regenerating the SID as part of the cloning process is not supported by Microsoft.
To solve this problem, Microsoft created the “System Preparation” or “Sysprep” tool. This tool can be used to remove specific information from the operating system so that it can be used to re-image multiple computers.
Clearly this tool should be used only and exclusively on a newly installed operating system, with the sole purpose of cloning it and then installing it on other machines through an image.
Using Sysprep is very simple. We can find it in the C:\Windows\System32\Sysprep folder, and we can run it from the prompt using this simple command line:
Sysprep /generalize /shutdown /oobe
The /generalize command removes all unique information from a Windows installation. Once Sysprep has completed the required operations, the computer will be shut down and you can then proceed to clone the disk to reapply the image of this system on other machines.
When the image is applied to a new computer and booted, Windows will show the initial Out Of Box Experience (OOBE) configuration screen, with which you can customize the information about the operating system again.
The /generalize command must be used even if the machines on which to deploy the system have identical hardware.
The /oobe command, on the other hand, is the one that causes the start of the cloned system on the new machines to take place in the configuration wizard mode, so as to allow the user or administrator to immediately customize their Windows installation and specify the license at first start.
For more information about Sysprep, read the related section of the Microsoft website: https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/sysprep-process-overview