Hi! I had long time a problem with 1TB Seagate on iMac 11,1, 27'' (late 2009) and it's brake before the new SSD 500GB came. I bought this iMac long time ago and it has on Mountain Lion but I think default was Snow Leopard but the previous owner didn't give me any CD/DVD. When the new drive came I will replace the old one but the problem is OS X. After repacement is it possible to open option Disk Utils (online), repartition and install OS X online? It will automaticly choose the Snow Leopard or Mountain Lion? Or I am in trouble. Thank you.