Found something on the SQL Server Magazine site:
For NS2.0 (SQL 2000): If Notification Services is installed on Windows, you will find this registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NotificationServices
http://sqlforums.windowsitpro.com/web/forum/messageview.aspx?catid=60&threadid=83588&enterthread=y
Below is a SQL batch that reads the registry and if someone who does have Notification Services is installed could run the SQL and it does find the registry entries, that would be a succesfull test.
Set nocount on
Set xact_abort on
Declare @registrypath varchar(200)
Set @registrypath = 'SOFTWARE\Microsoft\NotificationServices'
Exec master..xp_regread 'hkey_local_machine' , @registrypath , 'objectname'
SQL = Scarcely Qualifies as a Language