gPhotoShow can be used to create slideshows that can be easily started on your the local computer, Desktop slideshow is a slideshow that runs on the windows desktop, under all running programs.
Take a look at this video to see how desktop slideshow works
Run gPhotoShow Pro Slideshow Maker, then create a slideshow with you preferred settings, save them to a .gss file and from the Create menu choose "Run as desktop slideshow"
When running gPhotoShow will add an icon to the windows notification area, right cliick on it for operations on the slideshow
To easily start the slideshow when you wish click on the Tools menu to create a shortcut on the desktop
When promped choose "Desktop" for a desktop slideshow, "Full Screen" for a normal slideshow