I have this HP 620 laptop which has windows 7 installed on it. The laptop went thru the whole installation process fine. The problem started about two days ago. The laptop would start booting up and would suddenly just go off in the middle of starting up. I have tried the battery testing method, factory resetting the laptop. When it does show some signs of life, it would allow me to go as far as the window which indicates that windows has a problem would you like to launch the repair tool or start windows normally. I allow it to select the repair tool but when it get to zero seconds the time just starts all over again, until I select it myself and in this case the laptop just goes off. The on time is becoming shorter and shorter. Now it won't even allow me get this far. What could be causing this, hard-drive, power supply, motherboard, bad windows installation. Tried doing some searches online, no success. Your help is desperately sought in this matter.
Thank you very much for your kind assistance.