If you wish to change your desktop background on a regular basis without actually downloading new wallpapers, the Art of the Everyday Dynamic Theme is exactly what you need.
This new Microsoft theme was designed to automatically take care of your desktop wallpaper by retrieving new ones via an RSS feed, so minimum user input is needed after successfully installing it.
The downside is that an Internet connection is required to download new “everyday” wallpapers, but everything should work pretty smoothly no matter the operating system you’re running.
And speaking of operating systems, this new theme supports both Windows 7 and Windows 8, with compatibility for 32 and 64-bit versions. In addition, it can be deployed on ARM devices too, which include Windows RT and Microsoft’s very own Surface RT.