Does your Mac qualify for Mountain Lion? Not every system does, although if you're already running OS X Lion, chances are good that you'll be able to upgrade. Still, you'll want to check. The following hardware models will support Mountain Lion, according to Apple's specifications page:

• iMac (Mid 2007 or newer)
• MacBook (Late 2008 Aluminum, or Early 2009 or newer)
• MacBook Pro (Mid/Late 2007 or newer)
• MacBook Air (Late 2008 or newer)
• Mac mini (Early 2009 or newer)
• Mac Pro (Early 2008 or newer)

Mountain Lion requires 2GB RAM or more (we recommend putting in as much RAM as your computer can hold; it's probably the most cost effective high-value upgrade you can give your system) and 8GB of free hard drive space (we recommend 15-20 GB at least, preferably more).

You can upgrade from OS X Snow Leopard (OS X 10.6) as well as Lion (OS X 10.7). Make sure you update to OS X 10.6.8 first, the latest Snow Leopard release. From there, you can purchase Mountain Lion from the Mac App Store and install it to your computer.

Upgrading will not wipe away any user accounts or user data you have installed on your computer. For the most part, you can upgrade, and then pick up working wherever you left off. You may find that some apps won't make the leap, but most will -- although that's a topic for another post.

Not all Mountain Lion features work out-of-the-box on all systems. To use AirDrop, the feature that lets you share files between computers using configuration-free drag-and-drop, you need a fairly recent system: MacBook Pro (Late 2008 or newer), MacBook Air (Late 2010 or newer), MacBook (Late 2008 or newer), iMac (Early 2009 or newer), Mac mini (Mid 2010 or newer), Mac Pro (Early 2009 with AirPort Extreme card, or Mid 2010). My personal 2009 Mac mini doesn't support