Reinstalling DFS after upgrading Server 2008 R2 to 2012 R2

This weekend I used Disk2VHD to P2V a file server running Server 2008 R2.  Afterward, I wanted to install the Hyper-V Integration Components...which required SP1 for the OS...which required a reinstall of the OS...did all that...then upgraded to Server 2012 R2...and found that DFS shares were inaccessible.  These are my notes from troubleshooting.

1. Well, you're not supposed to re-install the OS of a DFS server (reference).

2. So I deleted the DFS namespaces and uninstalled DFS.

3. I couldn't re-install DFS.  Server Manager said "The request to add or remove features on the specified server failed.  The operation cannot be completed, because the server that you specified requires a restart."

4. Side note: Server Manager also said "Online- Cannot get role and feature data".

4a. Event Viewer contained the details - it seems that several old event log entries were corrupt or something and Server Manager couldn't enumerate them.

4b. So following instructions here, I backed up and then deleted the corresponding registry keys under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\WINEVT\Channels.

5. That made Server Manager happy, but I still couldn't install DFS.  So started reading the C:\Windows\Logs\CBS\CBS.log file...and found this little gem:

"Error...EventAITrace:Channel Microsoft-Windows-DFSN-ServerFilter/Analytic is declared by an existing provider DFSN-Filter{{564af62f-e581-4998-9991-c4bc18178815}}"
...an orphaned registry key still needed to be deleted...after that, DFS installed successfully.

6. After creating a DFS namespace, I was puzzled as to why it wasn't visible in \\domain.local...the fix was to add the domain controllers to the list of namespace servers:

7. Lastly, needed to search through all the group policy settings that my predecessor had setup and find where he had mapped network drive letters to the DFS shares so I could update them...fortunately, there's a handy GPO search function.