The Online->Create Boot Project will make it load your program on boot up. But there is something else that is often overlooked. If your hardware supports it, you should also see a Source Download. This will put the source code into the PLC so it can be uploaded allowing you to get online if you or the next person does not have the original program file. Whenever I start a new project, I always go to the Options dialog and set it to do a source download "implicit on boot project". This will ensure the boot project and source code remain synchronized.