As peter said we need a little more information. If the hard drive kicks on and you can hear windows starting up but there is no display - your screen may be dead. If you don't hear anything loading up the hard drive may be dead. If you boot up and hear a series of beeps we would need to know what the maker of the laptop / bios is then how many beeps you hear (this would mean a hardware failure / no power - which technically could be hardware).