ScreenSaver Commander(is free) handles the task of randomizing your Windows screensavers, and its other distinguishing feature is that you can configure it to prevent the screensaver from running when certain applications are open. It does other things like letting you manually set your screensaver. Its makers, Badevlav Software, also sell a shareware app called System ScreenSaver that lets you run ordinary programs as screensavers (and minimize all other apps, if you want), but the full version will cost you $10.