Yosemite Installation Error Okay, so every time I install Yosemite on my iMac, it gives me the same response. I delete the copy, and reinstall it, but it still gives me the same error...
Did you copy the installer of a drive? If you did, it's no good, as it will only work on the Mac that installed it. You will have to download the installer from the Mac App Store on the specific iMac you wish to install it on.