I had a look at the web page http://www.microsoft.com/windowsserver2008/en/us/r2-compare-specs.aspx with the different 2008 versions but I am still confused...I simply have to set up a LAN with AD authentication. There are about 100 users, just a few will be able to connect from outside. Is 2008 Std ok? I think I should buy 2 Win 2008 Std edition, one for the primary controller and one for backup. Correct? I think OEM Windows comes with 25 CALs, so I should add other CALs for the remaining users.Any missing feauture I should be worry about? Any suggestion for with step by step documentation (eitherr online or books)?Thank you for your suggestion.

You really only need to consider Enterprise edition if you are planning to use more than 4GB of RAM on the server and plan on using Clustering technologies. Otherwise, Standard edition works for most implementations. Visit my blog: anITKB.com, an IT Knowledge Base.

You really only need to consider Enterprise edition if you are planning to use more than 4GB of RAM on the server and plan on using Clustering technologies. Otherwise, Standard edition works for most implementations. http://jorgemederos.wordpress.com/ thank you for your answer.What I need is to set up 2 phisical servers with AD authentication. First server is primary controller. The second is backup controller. In this case do I need clustering (and Win 2008 Enterprise) or just 2008 Standard edition?

To build an AD domain with one, two, twenty servers, etc.., clustering is not needed. Clustering is gernally used when you want to provide applications with high availability solutions.Based on the only information you provided, my recommendation is to go with STANDARD edition. Here are the requirements for a Windows 2008 Server:http://msdn.microsoft.com/en-us/windowsserver/cc196364.aspx Visit my blog: anITKB.com, an IT Knowledge Base.

Franci_I agree with Jorge. Enterprise is only for using more then 4gb or RAM or if you want to cluster systems together. Otherwise Standard usually works 99% of the time.Miller-IT