Windows XP, you can sleep in the current state of the system memory is completely saved to disk when you next boot time, the system does not require loading, system initialization process and go directly to the state when you last sleep, so very fast start. But it will take a lot of hard disk space (and the same size as your memory), you can go to “Control Panel / Power Options / Hibernate” will be shut down to release the hard disk space, until the time when you need to use to re-open the can. Method is: Click “Start / Control Panel / Power Management / Sleep”, the “Enable Hibernation” before removing the hook.