How can I determine installed SQL Server instances and their versions?

Question

I'm trying to determine what instances of sql server/sql express I have installed (either manually or programmatically) but all of the examples are telling me to run a SQL query to determine this which assumes I'm already connected to a particular instance.

Answer 1

At a command line:

SQLCMD -L

or

OSQL -L

(Note: must be a capital L)

This will list all the sql servers installed on your network. There are configuration options you can set to prevent a SQL Server from showing in the list. To do this...

At command line:

svrnetcn

In the enabled protocols list, select 'TCP/IP', then click properties. There is a check box for 'Hide server'.