El Capitan Cannot start after upgrade

Hi JustJanet,

I have tried safe mode and reboot, everything worked well in safe mode and the system shows OS X El Capitan as well. So It means the operation system is installed. But somehow it doesn't start up.

So I called Apple Support. That's what she advised me to do which solved the issue:

1) Log in safe mode -> System Preference -> Users & Groups -> unlock to make changes
2) Select the Admin user -> click "Login items" next to the password

3) Delete all the items in there

4) Open Finder -> on the top menu -> select Go while press ALT at the same time -> a new folder "Library" appears
5) Click Library -> delete all of the files in these folders: Caches; LaunchAgents; Saved Application State.

6) Click Go on the top menu again -> Go To Folder -> type: /Library/Caches -> click Go below ->delete all of the files inside

7) Repeat the above -> type: /Library/LaunchAgents, then delete things inside
8) Repeat the above -> type: /Library/StartUpItems, then delete things inside if there is any
9) Repeat the above ->type: /Library/LaunchDaemons, then delete things inside

10) Restart computer to normal mode

11) It should solved, the computer should now log into the El Capitan perfectly. Then you can empty the Trash.

Try it, and let me know if it solves your son's Macbook!

Best,

Michael