Continously shutting off

I have a computer and when I go turn the power on it just shuts off. The longest I've ever had it stay on is 5 minutes. Sometimes the monitor is black with white printing asking if I want to restart windows normally or start from last configuration. It won't let me move the curser to pick the option I want whether using the mouse or the keyboard. It won't Even let me push enter. Alot if the time it just shuts off before anything comes in the screen. Is it done or is there a chance of fixng it? Please help!!!!!!