Ruined 2006 imac - Only allowed to reinstall Lion which is no longer availiable I have a 2006 imac which was installed with lion and now I've got it to a point where the OS became corrupt. I've put a maverick install on a bootable USB but when I boot from the USB doesn't give me the option to "Install OSX" it only gives me the option to "Reinstall OSX Lion" which doesn't work because that is no longer availaibile from the app store. I've tried to format the harddrive and that doesn't change anything.

My question is, how do I get the option to install a new OS fresh instead of only being given the option to reinstall Lion which does not work.
If you don't have your original OS X 10.4 "Tiger" install media, you'll have to obtain a retail version of any system up to 10.7.5.; 10.8 "Mountain Lion"
10.9 "Mavericks" and 10.10 "Yosemite" require a 2007 or newer iMac to be installed.

I've found a couple of supposedly original retail installation media for 10.7 searching on eBay for $35-$40 (1), (2); just be sure to buy the retail version and not the recovery DVD unless it is exactly the same that came your iMac model.

You can try your luck downloading the OS from a non official source, but I wouldn't recommend that.