Black screen on boot up

[Maritva]

When i turn on my toshiba laptop it does the initial load but before the log in screen can ever come up it black screens. I can't barely do anything with it. No mouse, doesn't accept keyboard commands like Ctrl alt delete. It doesn't allow me to start in safe mode.(pressing f8 does nothing). I don't know where to turn, also I don't have the disk to restart vista so that is out of the question. Help is greatly appreciated.