I did do that part, but I think you have solved the problem for me. I have built this server twice now and the first time I did it I followed a technote from Microsoft that tells you to use a boot.wim from a 2008 server CD. I did this and then tried to configure the WDS server by following the same technote. It is quite complex but I followed it through and then sysprepped a built XP machine to use as the reference PC. When I booted the PC and hit F12 it then launched the capture wizard. I had a few unrelated issues and messed around with the server and managed to break it.
So I rebuilt it after finding the windows-noob guide but used the Vista Business Upgrade CD to get the boot.wim from as it was the only version I had available to me at the time. Since then I have not had the capture wizard when I hit F12 only the install wizard.
Do yo think this was the issue?
If so should you consider posting on the guide you have that you must use a certain version of Windows Vista OR Windows 2008 Server as the source from the boot.wim file? Other than that your guide is far more easy to understand than several pages from the Microsoft site!
Many thanks
Neil