All versions of Windows XP have an "All Users" folders and its subfolders. It is an integral part of Windows and that is why it cannot be deleted. It was there before you created your second user and isn't something that has just appeared as a consequence of it. Live with it and learn to love it. If you leave it alone it will do you no harm :-) If you deleted your second user from Users in Control Panel it will have removed all that was necessary.