WallShuffler is a freeware program to randomize wallpaper with images in user specified folders. This program can be added to startup so that it will run automatically when your system starts.

Features:

• Add folders that contain images by clicking Add button or drag and drop fromWindows Explorer. To randomize wallpaper click Random button.To add program to startup click menu XProg -> Option then check Run at startup
• There are some options about wallpaper placement and size
• The supported file formats are Bitmap(*.BMP) and JPEG(*.JPEG;*.JPE;*.JPG)
• To run without displaying GUI, add -z parameter when call WallShuffler

Ссылка: http://vistanit..WallShuffler.exe