I aquired a beautiful 17" iMac, but it came loaded with Lion. It's sluggish I had to go to windows. Turned out finding out the model as the seller didnt know and advertised as a DVD rom, it is a Combo drive that reads and writes CDs and just spits DVDs out. I've been trying to get to snow leopard, leopard, tiger. I for some reason cannot get the mac to boot from USB. It's an intel core 2 duo mac it shouldn't have no issue. Does this mac not support USB booting? I need macrumor help!