When I start my G3 iMac (OS x 3.9) it gets to the desktop screen showing my wallpaper but does not populate the desktop with icons. The colored wheel just keeps spinning. When I hit the power button on the keyboard the window comes up to allow shut down with the buttons active but when I select shutdown or restart nothing happens. If I hit command/option/esc the task management screen comes up and allows me to relaunch finder but nothing changes. Also, the dock shows when I mouse down to it and I can select an app but it won't actually start, although it will show up on the task management screen and I can select and end it. I've been runing this operating system for a couple of years and haven't changed any settings or added new software in over a year. HELP!!!