All of our production instances of reporting services are split into the web server components and the reports database components.
I know that you can detect the instance of SQL Server on a database server by the following TSQL:
SELECT SERVERPROPERTY('productversion'), SERVERPROPERTY ('productlevel'),
SERVERPROPERTY ('edition')
However, in our case, the reporting servers do not have a database server components installed. So how do I detect what service pack is installed in this situation?