I am looking a way,to check if my .Net Application has been launched :
Best regards from Toulouse \ France
Environment.UserInteractive probably suits your needs.
It indicates weather or not the user is able to interact with the process or not. Which user launched processes probably are, and process launched from IIS/Task scheduler probably aren't.
https://msdn.microsoft.com/en-us/library/system.environment.userinteractive.aspx