I want to migrate from Windows 2008 32bit to Windows 2008 64bit in a single environment, that needs a clean install where the PDC machine is currently having file sharing, active directory and DNS role. I think that I can install over top of the current OS and rebuild the file sharing systems, but I dont want to lose all my users and AD objects. So, I have build a secondary machine on Windows 2008 32bit and promoted it to AD and also installed the DNS role. If I am going into the AD MMC snap-in, then its listing all my users as I expect. If I do a clean install now on my primary machine, then will I be able to run DCpromo and point to my new secondary computer to rebuild the AD tree? Or should I set the properties of the operational masters so my secondary machine which is the operational master and if so, what are the implications for my domain users? Thanks for any information.