How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dustin Your Own Question
Dustin, Mac Support Specialist
Category: Mac
Satisfied Customers: 13239
Experience:  Over a decade putting the missing byte back into Apple. Also worked in The US Army as A Network Switching Systems Operator/Controller
Type Your Mac Question Here...
Dustin is online now
A new question is answered every 9 seconds

Help please my MacBook Pro keeps showing a not allowed sign

Customer Question

Hi help please my MacBook Pro keeps showing a not allowed sign at start up
Submitted: 1 year ago.
Category: Mac
Expert:  Dustin replied 1 year ago.

Welcome to, my name is ***** ***** I will do my best to assist you.

Do you know what version of Mac osx you have installed? Snow Leopard, Lion Mountain Lion, Yosemite, Etc? ( 10.6 10.7 10.9 10.10 )

Also, do you have an install disk that matches your version of mac osx?

Customer: replied 1 year ago.
I don't know which version and I don't have the disk
Customer: replied 1 year ago.
It's from 2009, I bought it on Craigslist today
Customer: replied 1 year ago.
Expert:  Dustin replied 1 year ago.

Ahh.. Ok, lets try some steps that may work. Then we will move on to the harder stuff.

Lets start here.

Shut down your Mac.
Locate the following keys on the keyboard: Option, Command (⌘), P, and R. You will need to hold these keys down simultaneously in step 4.
Turn on your Mac.
Immediately press and hold the Option-Command-P-R keys. You must press this key combination before the gray screen appears.

Continue holding the keys down until your Mac restarts, and you hear the startup sound for the second time.
Release the keys.

Will it boot past the no entry sign now?

If not, lets try this next. Shut down the mac, start it and immediately press and hold the keys below.

  1. Hold both the Command and R keys on the keyboard until you hear the chime noise.

The Mac will now start in OS X Recovery mode. In recovery mode you should be able to choose reinstall osx.

I just seen your request for a phone call, which will cost more. Id like you to try the above steps first and see if they work, ( and save you the extra $$ for a phone call ) and if they dont then we can move to phone support.

I strive to provide great service, and greatly appreciate a rating of excellent ( 5 stars ) selected and submitted below this answer or at the top right of the screen. I always answer follow up questions.

Dustin S.

Senior Technician and Network Switching Systems Operator / Maintainer.

Customer: replied 1 year ago.
Ok now it says a window OS X UTILITIES
Expert:  Dustin replied 1 year ago.

Thats an improvement. lets try this, in the osx utilities window do you see where it says reinstall osx ?

If so, click that and start the reinstall. if not, then click utilities, then click disk utility.

Then click repair disk permissions first. Once that completes, go back to disk utility and click repair disk next.

When that completes restart the mac and let it try to boot normally. What happens then?

Customer: replied 1 year ago.
I Am installing OS X Yosemite right now
Customer: replied 1 year ago.
It says about 48 minutes remaining
Expert:  Dustin replied 1 year ago.

Perfect. lets put the phone call offer on hold for now.

I will be online till early evening. Please update me when the install finishes, or fails. Whichever comes first!

Dustin S.

Customer: replied 1 year ago.
Are you still there?
Expert:  Dustin replied 1 year ago.

Apologies for the delay, your message came right after I left for my lunch break. Ive just returned and read it.

I am here now. What happened with the OSX recovery?

Expert:  Dustin replied 1 year ago.

Hi, I never heard back from you after you told me there was 48 minutes remaining on the OSX recovery..

Is the mac working now?