Sysprep in Windows 2008

Windows Server 2008, on the other hand, has Sysprep built right into the OS, found at C:\windows\system32\sysprep\sysprep.exe. That's it -- just sysprep.exe.

In the virtual machine, you can run sysprep.exe either from the command line or from the GUI.
From the command line, enter:

sysprep /OOBE /Generalize /shutdown.

Note that if you enter Sysprep without any options set, the GUI will appear and prompt you.. It is important to use the /shutdown option rather than the /reboot option, since /shutdown allows you to make copies of the setup image (/reboot goes right to setup and creates a new machine). You can find more details on this in the Microsoft step-by-step guide on Windows Deployment Services update.