Where did you pull that SID number from? That type of information is not going to be found in SQL Server system databases. You will have to look at the OS Event logs. Another place would be the setup Summary.txt log generated at install. Viewing this in Explorer you can view who the owner of the file is that created it. This should show the user that executed setup.exe for SQL. {If everyone knows your local Admin password though your SOL}.

Can be found on most installations in:

<drive letter>:\Program Files\Microsoft SQL Server\90\Setup Bootstrap\LOG