Currently I have Leopard on my 2009 iMac and I wanted to upgrade to 10.6. So I had borrowed my friend's 10.6.4 Mac OSX Install DVD. I tried clicking on the INSTALL MAC OS X button and a screen pops up which says, "To set up the installation of Snow Leopard, Click Continue." By the time I click continue an error pops up which says, "Mac OS X Snow Leopard can not be installed on this computer." And I have already tried everything up to booting up from dvd. Please Help!!!!!