Updating os x to leopard
Though you should take a series of steps before upgrading to Mavericks, if you do nothing else – back up the Mac with Time Machine.
Do a complete back up, start one manually right before starting the upgrade process so that you’ll be sure to have the most recent backup handy.
One tip for people who have some of the oldest machines that are still eligible: You might want to wait just a few weeks before installing Mavericks and check to see what kind of experience people are having with it.
Once you've checked your hardware, it's time to check your software.Apple says you can upgrade to OS X Mavericks directly if you're running Snow Leopard (version 10.6.8), Lion (10.7) or Mountain Lion (10.8).