%programfiles%\Microsoft SQL Server\MSSQLnn.INSTANCENAME\MSSQL

This directory is also referred to in Microsoft's SQL Server documentation as <MSSQLPATH>\MSSQL.

It contains:

• sql_engine_core_inst_keyfile.dll
• … ?

Possible subdirectories are:

• Backup
• Binn
• DATA
• Install
• JOBS
• Log
• … ?