It is pretty common that I frequently am asked to take over a server with SQL on it sight unseen. Many times shops many not be fully aware if additional instances are or have been installed on their server. Since I am working on a set of scripts that we can use for discovery on new systems, I thought it would be handy to have a query that would give me a list of SQL instances with the version that are installed.
I found that this kind of information can be found in the registry which is accessible via a couple of undocumented extended procedures. Let me give the disclaimer right here…. Undocumented procedures from Microsoft are not supported and should not be used for regular production work. This is because they can change or be removed at any time. Now that I have stated that, the other obvious statement is that undocumented procedures can be pretty handy for some things, just use them with caution.
Click through for the script.