When we power off windows using hibernate mode, system will completely power down; according to Wikipedia:
"Hibernation saves electrical power. After hibernating, the hardware is completely powered down like a regular shutdown"
And we can boot it up using keyboard, mouse or through LAN; accouring to Microsoft FAQ:
You might be able to wake your computer by pressing any key on the keyboard, clicking a mouse button, or opening the lid on a laptop ... You can also wake some computers by turning them on remotely over a network.
So my question is this, How windows boot up when system is completely powered down by these methods? there is nothing on RAM so how can even windows control the system?