method 1:
Declare @Path Varchar (200)
EXEC MASTER.DBO.XP_REGREAD
'HKEY_LOCAL_MACHINE',
'Software / Microsoft / MSSQLSERVER / SETUP',
'Sqlpath', @ path output
Set @Path = @PATH '/ DATA /'
Print @PATH
Method 2:
Declare @Path Varchar (200)
SELECT @Path = filename from master.dbo.sysfiles
Set @Path = Ltrim (Reverse (@PATH))
Set @Path = Reverse (Substring (@ Path, Charindex ('/', @ Path), Len (@PATH)))
Print @PATH