http://support.microsoft.com/default.aspx/kb/938451

After using the command line described:

Wdsutil /Verbose /Progress /Uninitialize-Server

the services will not start, so the next step is to add the necessary files for WDS legacy to start. Run WDS legacy consol and it will prompt you for a CD then you will need to specify a Windows image name (don’t take the default as it is likely this is what you chose when you set the first CCS image up)

After this you will need to reinitialise the WDS server

Wdsutil /Verbose /Progress /initialize-Server /Reminst:<RIS REminst Folder>