David has a problem where his computer shuts off after awhile and he has to log in twice to get it back. Leo says he's had a similar issue with a MacBook. As long as he uses it every day, it's not problem. But after a few days, this issue would pop up. Leo just logs out and shuts down and that solves the issue. David should uncheck put the hard disk to sleep. He should also disable Power Nap. Those things may prevent this from happening. Turning off the Sleep function entirely will work as well, but he'll be using power then.