Mavericks re-install problems

[Fritz]

modelamac wrote:
holding the Option key at the startup sound. That gives you a choice of drives. Choose the Recovery Drive. Then chose Reinstall the OS. 10.9, and wait until it starts. The OS will be downloaded and the reinstallation will begin. Takes a bit of time, but it's worth it. No data will be lost. Use that time to set up a backup program for him, one that includes cloning a bootable backup so the next time he screws up he won't have to go through this again.

I talked him thru this. When it rebooted, it was still spinning the gear on the gray screen. But as suggested earlier, perhaps I should have had him wait 10 mins before saying it didn't take. We waited about 3 after reboot.
He knows now he needs an ext b.u., jic.