I've found a registry key:

Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL\Inactive\MSSQLServer containing 'MSSQL13.MSSQLSERVER'

I think it's seeing this and concluding that SQL 2016 is still installed.

I'm having the same issue. For me it was caused by a missing K: drive which was used for SQL Backups and default path for text search catalogs (unused!).
From...

Thanks for posting. You saved me loads of time.

Disabling cores does not reduce your licensing liability for SQL Server. Trust me - we've just been audited by Microsoft.

However, I notice for Windows 2016 (https://download.microsoft.com/download/7/2/9/.../WSSC2016LicensingFAQ.pdf ) you...

Thought I'd post this stored procedure in case it's of any use to others. I wrote it to execute a SSIS package synchronously from transact-sql, and use it widely in...