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

In my case the reason for the uninstaller getting stuck at SqlEngineConfigAction_repair_validation_Cpu64 were invalid file paths in the SQL server's system tables.

To correct this, allowing uninstallation, this worked for me:

1) Set service to use local account (Start -> Local Services -> SQL-Server->Properties -> Log on -> Local System acccount)

2) Follow the steps here: https://social.technet.microsoft.com/wiki/contents/articles/31786.sql-server-not-starting-after-fresh-installation.aspx

3) Retry uninstalling.

In case the above link becomes unavailable, here's a short summary:

• Start the SQL server service in recovery mode: NET START MSSQL$SQLEXPRESS /f /T3608
• Connect to server: SQLCMD -S .\SQLEXPRESS
• List the files referenced in system table: SELECT name, physical_name, state_desc FROM sys.master_files ORDER BY database_id; (go)
• Wherever the file path points to something invalid (like a missing drive), adjust it, using this: ALTER DATABASE model MODIFY FILE ( NAME = modeldev, FILENAME = 'C:\Program Files\Microsoft SQL Server\MSSQL13.SQLEXPRESS01\MSSQL\DATA\model.mdf'); (go) Note that the files have different NAMEs and different extensions (.mdf, .ldf)
• Exit sql server (exit)
• Shut down the service NET STOP MSSQL$SQLEXPRESS