Windows XP include an ultimate feature Hibernate in the power management features.Hibernate saves an image of your desktop with all open files and documents, and then it powers down your computer and When you turn on power, your files and documents are open on your desktop exactly as you left them.
If you want to leave your computer urgently then you can just leave it,Windows XP automatically put your computer into Hibernate mode after particular period of inactivity or Windows XP can detect that when your batteries are running low then it automatically put your computer in Hibernate mode to save your work before the battery fails.
If you want to do Hibernate then
1. Go to Control Panel then open Power Options.
2. Click on Hibernate tab,then select enable Hibernate and then click OK.
(Note : If you didn’t find Hibernate tab then that means your computer does not support this feature.)
3. Now it works automatically when Windows XP can detect that when your batteries are running low but if you want to do it then when you are going to turn off your computer then it shows you three button Standby,Turnoff and restart. At that time just press Shift key ( When you press shift key then it show you hibernate button) and then select hibernate by pointer.You will see your PC will shut down and when you turn on power of your computer you documnets,files are open on your desktop exactly as you left them.