I just recently bought a mid 2011 iMac. The previous owner has wiped the hard drive clean. The computer did not come with any sort of software restore disk. When I start up the computer it brings me to a pop up box with the option to install OSX Mountain Lion, but when I click on it, it asks for the previous owner's app store info. I can't get past this because the computer's HD is wiped and needs OSX to be reinstalled. I don't have a hard copy, nor have I bought OSX Mountain lion on my app store account. Thanks!