Desktop settings are missing??

On several windows 95 machines the display settings can not be adjusted. When you first boot up you can right click the desktop and access display properties. However, as soon as you try to click on settings an error comes up stating that there was an error accessing desk.cpl. After you OK the error you can no longer get to display properties unless you restart the system. Desk.cpl is in the correct location and is listed in the registry correctly. I have reloaded the video drivers and that didn’t do anything. I also started in safe mode and the problem also occurred. Any thoughts?