Hopefully this is the correct place to post this, apologize if the mods need to move it. So my sister gave me her old 2007 iMac that has a bad HD. I decided to upgrade the HD to an SSD but there is also a problem, she doesn't have the original discs. It had 10.6.3 loaded on the system before the HD crashed. So the SSD is installed, but I am not sure what to do next. Would I need to purchase The Mountain Lion installation from the Mac store on any of my current Mac systems and set up a bootable USB? Or do I need to find a set of original discs and install whatever OS it had originally and upgrade to Mountain Lion? ? I've seen a few articles online how to do this. Any help would be appreciated.