It's a function of the OS and you don't provide version information, etc.
Please read this FAQ for advice on how to ask your questions correctly for quicker and better answers:
How can I gain aceess to my O.S in order to turn that off?...My O.S is Mac OS X 10.5.8 does this help?
With such an old OS as Leopard 10.5.8, I don't think the OS is launching Photoshop spontaneously.
Sorry, troubleshooting a possibly corrupted temp Photoshop file will be a lot more laborious than I have time for right now.
Try googling it:
Thank You for the goggle link! This answer and solve the issue. It seemed I just had to go to my Photoshop icon on the dock, right click it and uncheck "Open at Login," duh me. Thanks for the Help!