Hi, So it's clear, if you're purchasing a machine with 10.7 (Lion) preinstalled on it. You will NOT be able to install 10.6.8 (Snow Leopard) as the only OS on the machine. The firmware of the board is made to run a specific OS. However you can run a virtual partition and use it that way. This should clear up the 25 threads I've read scattered throughout the chain this fine Friday morning.