I upgraded my G3 from OS 8.1 to 9.0 Now I get all the way through the extensions being loaded and just before the desktop should display I get a error type #10 message concerning the finder and the bomb. It will start with the extensions disabled. What should I do?

This soounds like a normal software problem. A lot can be figured out if you said which G3 you have. Try this: If you have the Norton Utilities CD boot off of it. You'll want to disk doctor and Speed disk you hard drive before doing anything else. But it is not required. Then Start up holding down the key to put you into the Extension Manager. Where it says "Selected Set" you wil want to select "Mac OS 9 All" After doing that restart. If that works then one of your third-party extensions is causing the problem. If the finder still crashes then you should backup/remove your system folder and preform a "Clean Install" If you Still have a problem you're gonna have to send your mac in to get repaired somewhere.