How to know SQL Server installation language while it is down? SQL Server is down after a security update.

I need to install a cumulative service pack which is language discriminated.

I'm downloading Spanish and English versions, I'm sure it will be either one, but it could be better to determine which it is while the server is down.
You can check the system registry to determine the installed language for SQL Server.  To get the name of the SQL Server Instance Key, first look at this registry key:


  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL


That key shows a list of installed instances; the Data column shows the registry key name to use when looking for the Language key in this key:


  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\&lt;name-from-previous-step&gt;\MSSQLServer\CurrentVersion\Language


This Microsoft site lists the various language IDs and the corresponding language name.

I wrote a quick blog post showing this process in greater detail at SQLServerScience.com.