Set As Background

A really simple way to display whatever jpg's or bmp's you like as wallpaper is with Phyle's Wallpaper switcher. It's a free program with no adware/malware of any kind.
http://philippebedard.net/category/4.aspx
You can create a folder wherever you please,put your pics in it and browse to it with 'setup' option in Phyllwall. You can set it to change to another pic(at random)in the folder from every minute to every six hours with a simple slider. It will change to another pic when you reboot and/or you can change pics by clicking on the icon in the task bar whenever you please.
I've used it since Win9x and it works very well with XP and doesn't hog resources at all..