As you know Microsoft is going to end its support for its one of the most successful OS, Windows XP in 2014.
So to celebrate this Microsoft has released an sidebar gadget for Windows Vista and Windows 7 users.
This gadget sits on your desktop and display the days left for the End of Support for Windows XP.
You may use following link to download it :-
P.S.You must be using Genuine copy of Windows to install it