WSUS downstream server broke shortly after a Microsoft Support ticket to fix Synchronization time-out issue. (involved manually deleting 3 SQL statement approvals). As this was one of 186 downstream servers, I doubt this is what caused it but in the interest of full disclosure, I thought I'd mention it.
Never the less, WSUS was down and I could not remove it and then once manually removed I could not reinstall it.
As this was a combination of a number of blogs, I thought I'd post the solution/process here:
I started with Lawrence Gavin’s excellent sticky note:
http://social.technet.microsoft.com/Forums/en-US/winserverwsus/thread/f447e7d6-7007-4eb6-b38b-90f92525e092
This got me part of the way there, but not without the tips in this blog:
http://blogs.technet.com/b/sus/archive/2008/11/05/how-to-manually-remove-all-of-wsus.aspx
This gave me the information to delete the SQL registry keys in step 8. As I was now able to install the Windows Internal DB via the Add Role function, I was still failing on opening service“MSSQL$MICROSOFT##SSEE (Error 0×80070424: The specified service does not exist as an installed service.)” during the setup. Ok, well that's progress at least....
Then I found this:
http://social.technet.microsoft.com/Forums/en-US/winserverwsus/thread/6da80d62-dd16-41bc-b00b-3616f3bc04f9/
Finally, after removing the recently installed Windows Internal DB and then overwriting the two machine .NET files (even though the current ones and the default had the same old date) this allowed the WSUS role to be fully installed. All through the process, this local error file was KEY, so I recommend anyone troubleshooting this to reference that on the server they are installing WSUS on: C:\Users\<YOURPROFILENAMEHERE>\AppData\Local\Temp\WSUSSetup
It was a roundabout journey over the last two days, but hopefully this helps someone else and shortens their downtime on this. Just goes to show you, without great blogs out there, I would have been dead in the water and doing yet another call with Microsoft Support.