my mother has a HP Pavilion dv2500 that will randomly just shut off. I've tried several start ups with battery in and charger connected, battery alone, charger connected and no battery and it's always the same. computer starts up and just shuts down. screen is working and it will get to the home screen but just shuts off. please help.
Try booting into safe mode. If you can that would mean a program starting with Windows is causing you to "boot loop". We could either find what is causing it and remove it or run a system restore back to before you were having this problem.
If you cannot boot into safe mode either your Windows installation may be corrupt or hard drive may be going out. HP is pretty good about putting hardware diagnostics on their recovery partition. Usually you get to this on HPs by hitting F10 repeatedly when the laptop is booting.