power supply..
U need a new power supply. The thing that transfer electricity to your computer in a way i dont know. However, why does the computer crashes? Because your power supply is too weak to transfer electricity to all your things in your computer (graphic card, harddrive, sound cars whatever you name it) and when your power supply is too weak the computer just chrashes itself and what i saw you said u need to take the plug once or twice or the comp wont start which to me meand that u have to press the start buttom on your computer twice (or am i wrong). however. Try get a new power supply you should see some difference i think.
http://mgi13.meritel.net/~mcr/cascade/i ... supply.jpg
A power supply if u dont know what it is (its usuall in the upper left corner inside the computer)