Howard,
when you say each install does not work, is this a bare bones re-install, or simply re-running setup? How much work has been done with this - are PCs connected and joined to the domain, for example? I would be tempted with a clean install (bare bones). If you need to keep the AD or data I would be tempted to create a domain controller inside a VHD (virtual PC) of Windows Server - these can be downloaded from Microsoft, migrate the FSMOs, backup everything important (or just everything), flatten the server, rebuild, join the domain that now exists inside the virtual machine, add the data back and off you go.
thanks
David