Follow the procedures from my previous blog, Clone a Windows 2003 Server with Citrix Presentation Server 4.X
Windows Server 2008 has Sysprep built right into the OS, found at c:WindowsSystem32SysprepSysprep.exe. You can run Sysprep either from command line or from the GUI.
From command line : sysprep /OOBE /Generalize /shutdown
From GUI (Remember Generalize or else WDS won’t see the system disk)