ok by looking at a different registry key and looking for Service names, i think this finds them all on my sample machine:
/*
ResultsId ResultsText
233 MSSQL$SQL2005
234 MSSQL$SQL2008R2
235 MSSQL$SQL2012
237 MSSQLSERVER
*/
declare @Results TABLE (ResultsId int identity(1,1) not null primary key,
ResultsText varchar(200) )
insert into @Results(ResultsText)
EXECUTE master..xp_regenumkeys 'HKEY_LOCAL_MACHINE' , 'SYSTEM\CURRENTCONTROLSET\SERVICES\'
select * from @Results
WHERE ResultsText = 'MSSQLSERVER'
OR ResultsText LIKE 'MSSQL$%'
Lowell