you have a large list and it is a bit intimidating to give much advice from where we type, and i am not too up on it honestly, but your thread had a lot of views and no posts so i did a bit of searching for you, start here-http://www.microsoft.com/windowsserver2003...generalfaq.mspx
after that , contact the vendor of the legacy software you are using, it is likely custom and you will need his/her help there to get it right. you also need to know how to set up an active directory and have knowledge of server administration. you would be wise to get some local help on this one. sorry i couldnt help any more. but remember, google is net users best friend!!