My photoshop won't work!, I'm back with more laptop problems. Options

[Tash]

OK, i found my photoshop disc, I installed it, and usally when it starts it come up with a welcome screen(saying stuff like "edit", "create"). Then when you click on what you wanna do, it would normally open up the credits and say loading then actually start up. But this never happened . I clicked on "edit" and the credit screen never came up! My dad says i have to reinstall it but i can't find the disc again! Is there any other way then reinstalling it? Please help me!