just got back from a vacation, and i accidentally left my computer on the whole week. but it was off when i got home except the power light was on. so i switched the switch in the back off, then on, then powered my machine on, loaded fine recognized all my drives and processor, then it was on the blue microsoft loading screen and it shuts off, but the power light is still on. tried everything again and this time it didnt even make it that far in the boot process........anyways.......halfway through the boot up period it just shuts off, but the power light is still on......is this a motherboard problem or a power supply problem???? or something i am unaware of.