Its a common situation. You can of course physically go to each machine in your company and check what is installed. But I'm a lazy DBA, or I try to be, and I want a solution that can let me have another coffee before lunch time.
If you do a Bingoogle search for something like "list sql server instances" you'll probably find these articles:
- http://thepowershellguy.com/blogs/posh/archive/2007/02/09/powershell-get-sqlserverlist.aspx
- http://sqlvariant.com/wordpress/index.php/2010/09/finding-sql-servers-with-powershell/
[System.Data.Sql.SqlDataSourceEnumerator]::Instance.GetDataSources()
I did. And when I did all I could think was "Sweet! How easy is that!?"
Sadly not as easy as it looks.