Repair/Remove/Install processes for SQL Server 2012 Express get stuck or hung

Question

An instance of SQL Server 2012 Express became corrupted somehow.
I suspect it was related in some way to my use of Entity Framework, but have no proof yet.

When

Answer 1

Here's what worked for me.

Solution 1:
- Stop the "SQL Server (SQLEXPRESS)" & "SQL Server VSS Writer" services and set their Startup Type to "Manual".
- Restart the PC.
- Run the repair process.
- Change the Startup Type back to "Automatic" and restart the services.

Solution 2:
- Stop the "SQL Server (SQLEXPRESS)" & "SQL Server VSS Writer" services and set their Startup Type to "Disabled".
- Restart the PC.
- Run the Remove process to uninstall SQL Server Express entirely (instance + shared components).
- Restart the PC again.
- [Optional] Run your favorite registry cleaner such as CCleaner.
- Install SQL Server Express (unless your goal was just to uninstall it).

NOTE: In the Solution 2 scenario, I tried the Repair process after the 1st PC restart, but it got stuck at step SqlEngineConfigAction_repair_validation_Cpu64.