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John T. F.
John T. F., Mac Druid
Category: Mac
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Experience:  20+ years in the computer/Mac industry
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Hi, I accidentally delete Mac OS and now I cannot reinstall

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Hi, I accidentally delete Mac OS and now I cannot reinstall it, I borrow an start up DVD from my friend and it stuck inside, what should I do?
Hello! My name isXXXXX will work diligently to provide accurate advice and information.

Do you know what version of OS X was installed on the MacBook?

Customer: replied 4 years ago.

it was lion mountain

Thanks Harry.

Did the MacBook ship with either Lion/Mountain Lion or was it originally running something older?
Customer: replied 4 years ago.

It was shipped with Lion

Customer: replied 4 years ago.

And I just wanna reinstall before sell it, but I guess I click the wrong button in Disc utility and now it is just grey screen

Ok. Please try the following and if it doesn't work simply reply back.

Shutdown your Mac.

Restart and, as soon as you hear the startup chime, hold COMMAND + R + OPTION keys until you see the Apple/network logo and progress indicator (Alternative: press the “OPTION” key at boot and select the “Recovery HD" option in the menu).

Wait for “Mac OS X Utilities” menu to appear.

Choose Disk Utility.

In Disk Utility, choose your hard drive from the listing in the left sidebar and then choose the "Partition" tab.

Under Volume Scheme, click "Current" and choose "1 Partition".

Name your hard drive on the right side (usually "Macintosh HD") and choose "Mac OS Extended (Journaled)" as the format.

Click options and verify GUID partition table is selected and click OK.

Now click Apply.

Once the process has completed, exit Disk Utility and attempt to install OS X.

Select the option to Re-install OS X... and it should guide you through the process after that.

If you continue to have questions on this topic, just reply back to this discussion. I will be more than happy to work with you further. Hopefully, this info will answer your question. If so please, please remember that when you are asked to give a rating, you are rating my personal service only and not this website itself or your issue.

Thanks and good luck,
Customer: replied 4 years ago.

Thanks, XXXXX XXXXX it is downloading something from internet???

Yes, it should be downloading an emergency recovery package to get you started.

John T. F. and 2 other Mac Specialists are ready to help you
Customer: replied 4 years ago.

Thanks very much, It is installing now.



You are very welcome!

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