Can’t upgrade Windows Server 2012 Essentials to Windows Server 2012 R2 Essentials

I've been testing Server 2012 Essentials. In short, you can connect XP clients to the domain and use the shared files/folders and printers. However, XP and Vista are second class citizens on Server 2012.

• You cannot use the server's Connect Wizard (http://servername/connect) to connect XP or Vista clients. You can use the standard XP Network ID wizard to connect to the domain. I believe this means you won't be able to use the user's current profile. (Several years ago I remember using a registry hack which allowed us to redirect to a different user profile. We had to change file and folder permissions on the old profile first. I do not know if this registry hack still works.)
• There is no special client software for XP or Vista unless Microsoft releases something separate in the future. I think this software is what performs the backups. What else it does I don't know.
• XP and Vista clients cannot be backed up using the server based backup solution.
• Oddly, on the server XP clients do not show up under Dashboard > Devices or under Dashboard > Home > Quick Status > Computers. However, XP computers do show up in Active Directory > Computers.
• The Implement Group Policy option in the Dashboard > Devices does not affect XP or Vista clients. However, you can administer Group Policy to XP and Vista clients using the standard Server 2012 Group Policy Management Editor.

I haven't done an installation of Windows Server 2012 R2 Essentials into an existing Windows Server 2012 AD domain, but I just did an install into a Windows Server 2003 AD domain last week and it worked fine. I was able to join the existing domain, promote my W2K12 R2 Essentials machine to a DC, and then retire the existing Windows Server 2003 DC. It worked out just fine.

Were I in your situation I'd:

• Join a temporary virtual machine to the domain (running W2K12 Standard in evaluation mode if nothing else)

• Demote the current W2K12 Essentials DC back to being a member server

• Move any files off the "C:" volume of the W2K12 Essentials machine you need to save

• Reformat the "C:" volume and install the new W2K12 R2 Essentials software as a replica domain controller on that machine

• Migrate files back to the new W2K12 R2 Essentials machine

• Complete the installation process ending with demotion and removal of the temporary VM

I'd mock this up with VMs before I actually did it, just to be sure it all worked smoothly in real life. It looks like a solid plan to me.

I wouldn't do any kind of "backup / restore" of AD, or any type of AD migration. Using AD's existing replication functionality is the way to handle this problem.