How to use Recovery Mode When Your MacBook Fails to Boot

If your MacBook fails to boot, there are some things you can do to retrieve your data and make your MacBook work. Recovery mode is specifically designed for this purpose.
Using Recovery mode is quite similar to using your usual Mac interface. Here’s how to use it to rescue your system.

How to Use Recovery Mode to Resolve Disk Errors.

1. Hold down Recovery Keys after you Turn On
Press the 'Power' button, then immediately hold down the ‘Command’ and ‘R ’ keysuntil you see the ‘Apple’ logo. You will now be booted into Recovery mode.

2. Select ‘Disk Utility’
Select ‘Disk Utility’ in the dialog box that appears. You will be taken to the ‘Disk Utility’dialog box where you can repair a specific disk.

3. Hit ‘First Aid’ and ‘Repair’
Select the volume in which macOS has been installed. After this, hit the ‘First aid’ button. Select Run in the pop-up that asks for confirmation. ‘First aid’ will start repairing your disk.
If repairing your disk does not solve the problem, you will have to reinstall macOS.

How to Use Recovery Mode to Reinstall MacOS.
1. Select ‘Reinstall OS X’
After getting into the Recovery mode as instructed above, hit the Reinstall OS X option and press ‘Continue’. A screen asking you for confirmation will appear.

2. Confirm to ‘Continue Installation’
Select the ‘Continue’ button on the confirmation screen. Another pop-up will appear, saying the computer’s eligibility will be verified with ‘Apple’. Hit the ‘Continue’ button. The ‘Terms and Conditions’ page will appear.

3. Agree to ‘Terms and Conditions’
Agree to the ‘Terms and Conditions’ by clicking the ‘Agree’ button. A screen asking you to select the disk for installation will appear.

4. Select ‘Disk and Install’
Select the disk on which macOS was originally installed and press the ‘Install’ button. After downloading the files and installing the OS your computer originally came with, the system will restart. Just follow the on-screen instructions to have a fresh macOS.
Before proceeding with reinstalling the macOS, make sure you have backed up your data and erased the disk in Disk Utilities.

You will have no longer have problems booting your MacBook.