A PowerShell 2.0+ script that sets the desktop background to a randomly chosen image out of a pool of images. Optionally, you can use different pools of images, dependent on the date (useful for having Christmas desktop backgrounds appear only in December, for example). A pool will go through each of its images one time and then start over. Pool usage history is saved in an XML file in the same folder as this script. Intended to be run as a scheduled task. If your desktop backgrounds are stored in a folder named "Desktop Backgrounds" within your "Pictures" folder, you can go to the next step. Otherwise, you will need to open the script in an editor and modify the path used in the Get-Default-Pool function to point to the correct location.