Restart windows without restarting your pc

This works both with windows vista and xp.
so here's the trick..

Windows vista :

Select Start, then hover over the right arrow that is to the right of
the padlock icon until the pop-up menu appears that contains “restart”
as one of it’s choices. Hold down the SHIFT key while clicking on the

“restart” choice.

Windows xp : 

 

Select Start. Select “Shut Down…”. Change the drop-down combo box under “What do you want the computer to do?” to “Restart”. Hold down the SHIFT key while clicking on the “OK” button.