Daniel Carter said: >thank you very much, but one question at the outset: will I most >likely or not have to erase and install? If you mean "erase your hard drive", I wouldn't recommend doing that. It depends on what you are trying to accomplish, but in most cases I would recommend an archive and install: http://docs.info.apple.com/article.html?artnum=107120 ...which doesn't erase anything. When you are sure that you no longer need your old system software, you will be free to drag it to the trash and trash it. I think that you will find that upgrading is surprisingly easy. Randy B. Singer Co-Author of: The Macintosh Bible (4th, 5th and 6th editions) Routine OS X Maintenance and Generic Troubleshooting http://www.macattorney.com/ts.html