I repaired a MacBook Pro which had been powered off for an extended time and couldn&#x27;t load OS X onto it. Turned out it was using hardware time to determine if a cert was valid when validating the OS X install image. (Validation is done by the downloaded installer so I infer that it was trying to make sure the download was okay and was not trying to prevent third-party OS installs). I fixed it by spawning a shell from the installer and setting the date the unix way -- but what is a mere civilian supposed to do?