Sorry to bring this thread back from the dead, but I thought I would offer my dreadful experience with this exact same issue.
The whole issue started because of SQL server backups...that's right, it shot itself in the foot. Not sure why, but performing a maintenance plan backup put the "model" database into some sort of forever "restore" mode. Upon restarting MS SQL server, nothing will boot. The tempdb requires model apparently, so SQL server will not boot until model is not in restore.
Unfortunately, none of this methods in this thread work. Restoring from backups would never work, because of the "HResult 0x6D, Level 16, State 1
Shared Memory Provider: The pipe has been ended." error. That is really the issue, I'm guessing this is some sort of SQL Server bug. Searching google for the error brings up more people with the model db restore issue but no solutions.
I also tried the tempdb copy and rename to model, that did not work either.
My ultimate solution was to restore to a previous VMware snapshot..thank god for those, otherwise we would have been screwed. Luckily I'm primarily an Oracle DB, only doing this SQL server crap because I had to, but what a nightmare..all because of trying to backup. :crazy: