cant get passed the black *system is starting * screen

Help please . I have been having troubles with my computer lately where if I happen to reboot I have to fight with it several times before it will do a complete boot up . I get stuck on the very first screen, the system start screen where you can interrupt normal startup.. ( which I can not do either)... now it goes past that screen I get the little curser blips in upper left of screen, then a black screen and nothing :-(

 

what operaing system??
more details please

 

if you are running windows?...then try booting in safe mode or debugging via F8. Hit F8 when you start up your computer and it should take you to a help screen with booting up.