How do I find the data directory for a SQL Server instance?

Question

We have a few huge databases (20GB+) which mostly contain static lookup data. Because our application executes joins against tables in these databases, they have t

Answer 1

Small nitpick: there is no data folder, only a default data folder.

Anyway, to find it, assuming you want to install for the first default instance:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.1\Setup\SQLDataRoot

If there's a named instance, MSSQL.1 becomes something like MSSQL10.INSTANCENAME.