Black screen after changing resolution

Was installing windows onto my laptop and went to change the screen resolution, clicked something and the screen went black. I have it hooked up via hdmi to my tv because the laptop screen is cracked an I can't see anything on it. I have turned it off an on even taken the battery out an still a black screen. I've pushed f8 on start up but nothing has worked, any info to help get my screen back would be appreciated :)