Hello, My current 'internal' Windows 2003 domain name contains an underscore (_). Will that still be compatible when I upgrade to Windows 2008 server? Also, can I add a new Windows 2008 member server to my current Windows 2003 domain or does it have to be a DC? Thanks....

You can add Windows 2008 to Windows 2003 domain as member server. NetBios domain can have _ in its name, but DNS name should not contain underscore Check this http://support.microsoft.com/?kbid=909264With kind regards Krystian Zieja http://www.projectnenvision.com Follow me on twitter My Blog

Thanks.... Now also in line with attempting to keep a 'seamless' transition to W2008 from W2003 since I'm only replacing hardware, I'm thinking of adding two new W2008 DC's into the current domain, then take the two current W2003 DC's offline & rename the two new W2008 DC's with the same two names of the W2003 DC's as an 'in place' swap. Also want to add a W2008 member server as my mail server. Your thoughts?

You will need to prepare the domain before you can add any 2008 DCs Preparing your Active Directory Infrastructure for 2008 http://www.anitkb.com/2010/03/preparing-your-active-directory.html With regard to your plan on retiring and then renaming the new DCs to use the old names, that will work. Renaming DCs is supported and usually does not cause any issues. However, you should do this change during a scheduled maintenance windows as you may impact certain services during the time you make this change until the changes proprogate. Make sure that when you retire a DC, wait for the AD related objects in AD and DNS to be removed and replicated. Otherwise, you will encounter some issues when trying to rename the new DCs. Visit: anITKB.com, an IT Knowledge Base.

Thank you....