pulldown box is disabled on screen saver

Where in the registry is the setting that would control the pulldown list box that is on the Screen Saver tab of the Display Properties settings. I’ve fixed the SCRNSAVE, ScreenSaveActive, ScreenSaverIsSecure, ScreenSaveTimeOut. The screen saver will activate based on the ScreenSaveTimeOut, and you can see the screen saver’s name in the pulldown box–greyed out. I’ve looked through many tech notes related to the screen saver and can’t find how to turn this back on.