Had SQL Server 2008, using SQL Server Installation Center to ugprade to SQL Server 2014 Enterprise. I'm on Windows 7. Ran into some issues.
Everything went smoothly using the upgrade wizard, but near the end I got an alert telling me that it couldn't complete some parts of the installation process because my workstation needed to be restarted. The last page had a few green checks and a few red X's, but I didn't hang around to check what they were - closed everything, restarted computer. Went back after restart, ran the upgrade wizard again - now it fails at the Instance Configuration step with the error message "The Instance ID 'MSSQLSERVER' is already in use by SQL Server instance 'MSSQLSERVER.INACTIVE'. To continue, specify a unique Instance ID.
Tried researching problem, came to a blog post about fixing a failed SQL Server install/upgrade that involved running msiexec /x from the command line, but that solution didn't work for me either - the command line uninstall led to a dialog saying that it failed to uninstall.
Current state is that there's a SQL Server 2014 folder in my start menu, but SQL Server Management Studio is missing from it. If I open my database in SSMS 2008, it says the DB version is 10.0.5512 - post upgrade, I gather it should be at least 12.0.
Is there any way for me to salvage this installation without uninstalling everything, losing all my DB configurations, and starting clean?