loptop

If you want help you need to provide information like barand and model of computer, OS running and any service packs.
You also have to explain what you mean by never starts...any lights, any beeps, endless boot loop, any BSOD, lights on but black screen? You get the idea. Provide as much information as possible.

What have you tried? Did you press a key to get into the BIOS? Have you removed the battery and tried booting just connected to the power?