If Windows XP is being used, then changing the XP serial number is easy.
Automatic Wallpaper Changer is a free Windows software, that belongs to the category Desktop cust
You might have to change your Windows product key if your current key isn't valid.
BootSkin is a program that allows users to change their Windows boot screens.
With Changer XP, there would be little trouble but fun to set your favorite images as your boot screen, desktop
Changer XP Download – softpedia.Com
Besides, the screen saver programs can run in the order you like.
Need to change XP serial number – Geeks to Go Forum