I would like to purchase a MacBook for my wife, but will need to upgrade the RAM to 2 GB and would later like to purchase the Apple Care extended warranty. Given that two 1 GB sticks of RAM runs $80 and upgrading via Apple costs $158 (with education discount), I would rather do the job myself. But I also know we'll need Apple Care to cover the laptop while we're in law school. Will installing RAM that is not "Apple Approved", or an installation done by someone who is not an Apple authorized tech (yours truly) make purchasing Apple Care impossible? Will it void the warranty? Thanks in advance for your help.