So I bought an old Mac Pro 1,1 from 2006 and I have been trying to install any OS on it for the past 12 hours. I'm about to give up and flip it. I aquired a retail version of Lion 10.7 which has the InstallESD.dmg inside the Install Mac OS X Lion.app file. I formatted my USB drive as Mac OS Extended (Journaled) and Master Boot Record, then I hit Restore on the new partition, and I selected the "Mac OS X Install ESD" (the InstallESD.dmg which I mounted). I proceeded and everything went well. I plugged the drive into my Mac Pro, held down <OPTION> and I selected the drive. After a minute or two, I got yet another "The OS X Installation couldn't be completed" followed by a really, really large log file. Am I doing this wrong? Do I need to patch some files to install a legit OS on a legit Mac Pro machine? I would argue this should work, but for some reason it does not work. Any help is greatly appreciated! I'm so close to calling this a dead project. Thanks a lot.