Any application that accesses the display adapter to draw a fullscreen generally resets the display to its non-fullscreen settings (resolution, color depth, refresh rate) when the application is exited. When you restart your comp with a fullscreen app running, the app may exit, but the display adapter usually does not have time to reset. If you are too impatient to let your computer do its job, then don't be surprised when your computer fails to do its job.
@CatBoy1235 how old are you. Ok school sucks I agree that(mine started yesterday), but I wanna to get some good job, so I go to school and ewen outside and that what you should do too before you start avoiding other people and before than you cant even watch out 'cos yor eyes start hurting. And i dont wanna say that its wrong to be nerd (we all are) not just too much. Damn this is hard to do this with phone.