I'd like to upgrade to OS 10.3, but I don't want to lose the settings for my installed programs which are stored in each user profile. Can I install 10.3 from the CD just like a regular update which will update the installed programs and add new features without damaging anything? Does a full support contract come with the purchase? I was surprised that AppleCare for the computer stops whenever a problem arises related to a network or anything that requires use of the root user. At least the people at the Apple Store aren't like the stubborn ones on the phone and will really try to help with any Mac issue.