I do not need a solution (just sharing information)
The release notes of DS6.9 SP6 does not mention on what server it can be installed. (DS6.9 SP5 used to be Windows 2003 or Windows 2008).
Is it now Windows 2008 or Windows 2012 ??
For WinPE 4.0 you have to download ADK 8.0 from Microsoft. This ADK is not supported on Windows 2003 (and 'ADKSETUP /list' will not list the WinPE on Windows 2003)