Messenger Starts when Outlook accessed

I was told that if you change the name of Messenger in the program folder by going through "my computer" "C Drive" Right click on the messenger folder and change the name, it would not start any more when Outlook started, well everytime I start outlook it creates a duplicate folder with the messenger name, each time I change it, and each time I log in, voila, there irt is again.How can I stop the messenger from loading along with Outlook?