How to make fun on a Friend's PC

You know the use of Print screen button on the keyboard [present on top right above insert] .
It captures the screen , right ?
But now I will tell you how to use it for some fun .
Take screen shot of the desktop by pressing Print Screen on the desktop .
Go to Paint and paste this .
Save it .
For Windows XP users

1) On the desktop right click -----> arrange icons by ----> De-select 'Show Desktop Icons '.
2) Now right click the taskbar and select properties .
3) Check auto hide the taskbar. Click OK.
4) Now change your wallpaper and keep the one you saved earlier.
5) If paint is not closed, select File ---------> 'Set as background (Centered) '.
Now on the desktop even if you click any icon nothing will happen !!!
Now do I need to tell youhow you can use it for fun on someone else's PC ?
To revert back to normalcy change the wallpaper and select 'show desktop icons' on the right click menu .