Hi, I just bought an IMac at Goodwill. It's a G3 of unknown speed with 92mb ram and a 6gb harddrive. When I turn it on, all I see is a little file in the middle that switches from the Mac smiley face to a question mark. I'm assuming, since Goodwill erased the harddrive, that the computer doen't have an operating system at all. What do I do? Is there a place I can download an older operating system, burn it, then put it on the IMac? Also I should note my main computer is a Windows machine. Yikes! Any help would be great.