What Is A Bootable Device For Mac

  1. What Is A Bootable Device For Mac Os
  2. What Is A Bootable Device For Macbook Pro
  3. What Is A Bootable Dvd
  4. What Is A Bootable Device For Laptop

How to Set the Computer Boot from the Bootable Media. Step 1 Connect your external drive to your unbootable Mac. Step 2 Press down on the ‘Option’ key after restarting your Mac. Step 3 Once the booting has finished, your Mac will display the Startup Manager to show you the available boot drives. Select your external hard drive. Download Windows ISO file. Go to the Microsoft official website and download the free ISO file for.


If your computer pops out message ”No Boot Device is Available” error, there are some problems on your windows system, but no need to worry about that, this article will show you how to fix”no bootable device is available” error for totally free if you are seeing this no bootable device error on Dell HP ACER ASUS TOSHIBA LENOVO in Windows 10 8.1 or Windows 7 computer.

Table of Contents

  • How to fix Computer No Boot Device Available Error Problem?
    • Fix no boot device available error due to active partition error(tested)

What happened when your computer says No Boot Device Available?

When your computer pops out a message says no boot device available error often means the computer operation system is not available to find the bootable hard disk, so it can not start to boot, so if you want to know how to fix it, you need to figure out why your computer system can not find the boot device.

Here are some causes, you can check if your computer is at the same situation.

Fix no boot device available error

Causes of Computer No Boot Device Available Error

What Is A Bootable Device For Mac Os

1. The computer just has been misled to boot from an unbootable hard disk or device

If you attached an external hard drive or USB and wrongly set it as a boot device, or you used to change your PC boot device order, these actions may lead to no boot device available error. In this situation, you can check your boot device order in BIOS mode.

2. The computer internal hard disk gets jammed/damaged or corrupted somehow

When your internal hard disk get jammed or damaged somehow, your computer may also reports that no boot device available error. You can check the disks status and running diagnosis.

3. The computer's boot hard disk MBR sector has corrupted somehow

The MBR sector is a hard disk that contains operating system files and drives required to start a computer. Therefore, once this drive is damaged, such PC “boot device not found” issues will happen.

4. The Operating System has changed configuration settings or damaged disk

Normally “no bootable device available” issue is caused by operating system errors. For instance, your OS updated its system files or experienced file losses when it frozed? I wouldn’t deny that those situations may occur during daily use. Doesn’t matter what is the cause of it, check your OS files and folders might be a solution to it.

5. The computer infected with virus

Trojan is the biggest nightmare for any internal hard disk and it can damage the hard disk MBR sector, OS files and folders, as well as internal hard disk and even more somehow you will have to deal with it eventually. We truly hope it have not done any harm.

how to fix no boot device available error

How to fix Computer No Boot Device Available Error Problem?

1. Check or reset the boot order on your PC.

First, you can check or reset the boot order on your computer system, steps are as follows:

Step 1: Turn on your computer and press 'F2' button to switch to BIOS mode.

Step2. Click 'BIOS Setup Utility' option bar and select 'Advanced BIOS Features'.

Step3. Highlight 'Hard Disk Boot Priority' area simply check or reset your bootable hard disk on top of the boot device list.

Step4. Press 'Esc' to re-start your computer. Generally, your computer will operate well beyond any of your expectations. when “no boot device available”happens, it often means you set a wrong boot disk.

2.Fix no boot device available by resetting the BIOS configuration

Step1: Go to BIOS mode by pressing “F2”.

Step2: Make sure the “SATA-0”, “SATA-1”, “SATA-2” all on, if there are off, computer cannot find the boot drive.

3.Fix “no boot device” error with Troubleshoot

The second tool you can try is Troubleshoot.

Step1: Insert the Widows 10 bootable installation DVD. Click the “Repair your computer” on the left corner of computer screen.

Step2: click “Troubleshoot”, and enter “Advanced options”.

Step3: click “click Automatic Repair or Startup Repair” in the advanced options. Wait for a while, after this process, restart your computer.

4. Fix no boot device available error due to active partition error.

If there is more than 1 active partition that boots the system, then Windows does not know which one to boot. This may happen due to your using of Disk Management or other disk mange software to adjust the disk partitions before the error happens, the problem may exist on your hard disk.

How to fix active partition error?

1. You can take your disk out and insert in on another computer. (Or use Diskgenius usb bootable edition)

2, Check how many active partitions are there on the disks. If there is more than one active partition, set the rest except the c drive inactive. (use DiskGenius which shows as following photo and use its 'set inactive')

3, Keep the c drive as active only, and the error can be fixed.

What Is A Bootable Device For Macbook Pro

Why? Active partition is set as bootable partition which contains operation system. When other partition is set as active, system cannot find the boot partition so there will be a boot failure.

Also read: 3 ways to set partition active with freeware

5. Check, Repair or Reinstall Computer Operating System.

After these steps, if your computer no boot device available error is not solved, you can check the operating system files and folders. If the problem happened because of unexpected deletion, try to recover them first with our undelete file recovery software. If they can’t be restored, try updating or reinstalling your operating system to see whether the same “no boot device available “error message pops.

6. Check or restore MBR sector from your boot hard disk.

There is another possibility that your no boot device available error is caused by bad MBR sector on your boot hard disk. MBR is master boot record, check and restore your hard disk MBR sector will help you repair it. Command line can help you solve this.

Step 1: Backup the MBR by a command:

“dd if=/dev/sda of=/path-to-save/mbr-backup bs=512 count=1” (“path-to-save/mbr-backup” is the path where you want to save mbr-backup)

Step 2: Restore the MBR by a command:

“dd if=/path-to-get/mbr-backup of=/dev/sda bs=512 count=1” (“path-to-get/mbr-backup” is the path where you have the mbr-backup stored.)

7. Run antivirus software or format your hard disk to clear the virus

And your“boot device not foundr”error may also caused by virus infectious, you can run a antivirus software or format your disk to clean the virus.

Recover the data on your computer

What can you do when your device is not accessible? iCare Data Recovery Free is 100% freeware for a inaccessible device recovery that you may download it here.

Plus Most of the solutions may format your data on the disk, if you want to make sure the safety of your data, you can use a professional data recovery tool to restore your data from your unbootable hard disk.

Notice: Choose a read-only program, which will do no harm to your data.

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File Recovery Free > Format Recovery Utility > Howto > Fix computer no boot device error

Sep 21, 2020 • Filed to: Solve Mac Problems • Proven solutions

Creating a bootable drive for your Mac certainly seems to be a wise decision to make. Even though the macOS recovery partition can take care of all your recovery requirements in times of need, it’s still worthwhile to have a bootable installer.

Why Do You Need to Create A Bootable Drive For Your Mac?

What Is A Bootable Device For MacBootable
  • The Mac installer gets deleted as soon as you download it and use it by installing the Mac operating system. Once the installer gets deleted, it means that you can no longer use it to install the macOS on another Mac device. You will have to again download the installer on the latter Mac to install the macOS. This can take a lot of time and become inefficient if you have multiple Macs.
  • Clean installs can be performed by installers which are very helpful in overwriting your start-up drive. You can also use this function for other troubleshooting issues as well.
  • When you have a bootable installer, it ensures that you are well guarded in an emergency scenario by making use of some of its helpful utilities.
  • A bootable installer can allow you to install an earlier version of macOS and also let you temporarily boot into the previous version of the macOS.

What Do You Need Before Creating Your Bootable Drive?

Before you begin the process, you will need the following:

  • USB Stick / External Hard Drive: If you are planning to use a USB for downloading the bootable version of the installer, make sure that it is 8GB in size or larger than that. In the case of Sierra, 12GB is recommended as the minimum requirement. Ideally, 32GB to 64GB is a good size to have as it is not only cost-effective but also gives a better performance. In the case of an external drive, you can use any spare one that you are not going to use for any other work.
  • Download macOS High Sierra Installer: It is important to note that once you have downloaded the installer, it will begin with the installation process on its own. You can close the installer just like you quit any Mac app. In the case of the macOS version being older than the current one, you can click on ‘ok’ once the message flashes that the version is too old to install. You can find the old installer file in your ‘Application Folder’. Don’t forget to take a backup of your Mac to be on a safe side.

Part 1. How to Create a Bootable Drive Using Terminal

There are two ways of creating a bootable copy of the installer. You can either use Terminal or get the job done through a free software like Recoverit to do it for you. First, let us look at how to create a bootable drive using Terminal.

Steps to create a macOS Siera beta boot disk:

  1. The first step in the process is to connect your external hard drive to your Mac. You need to name your external drive ‘untitled’ for the Terminal command to work.
  2. Launch Terminal. You can find this in the 'Utilities' folder of your Applications folder.
  3. Copy the following instructions now:
sudo /Applications/Install macOS Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install macOS Sierra.app
  1. In this step, you have to paste the copied instruction on the screen by going back to the Terminal.
  1. You will be required to feed in your user password now and then hit ‘Return’.
  2. Now, the Terminal will ask for your permission to erase the drive. To continue, type ‘Y’ and again hit return.
  1. After the Terminal has erased your drive, your Mac will prompt you if you wish to use the drive for Time Machine. Click ‘Don’t Use’.
  2. Next, the installer file will be copied by the Terminal to your drive. This might take some time, so be patient.

What Is A Bootable Dvd

  1. Once the copying is completed, a ‘Copy complete’ message will be displayed on your screen. You can now quit the Terminal and use your drive.

Part 2. How to Create Bootable Media for Mac with Recoverit Mac Data Recovery

Recoverit Mac data recovery software is one of the most impressive and easy-to-use data recovery software in the market, and it has lots to offer with its varied utilities and functions. With Recoverit to create bootable media, you can access your system easily without the need to reinstall the macOS to recover your lost data.

Step 1 Launch Recoverit and get to select 'Computer Crash Recovery'. Click 'Start'.

Step 2 Choose your connected external hard drive as the bootable media, and click 'Start'. You will receive a requirement of formatting the device. Before the formatting, remember to back your drive data up.

Step 3 Wait for a while, and Recoverit will format your drive and start creating the bootable media.

Step 4 Once it finishes, follow the next steps to restore data.

Part 3. How to Set the Computer Boot from the Bootable Media

What Is A Bootable Device For Laptop

Step 1 Connect your external drive to your unbootable Mac.


Step 2 Press down on the ‘Option’ key after restarting your Mac.

Step 3 Once the booting has finished, your Mac will display the Startup Manager to show you the available boot drives. Select your external hard drive and hit ‘Return’.

Step 4 If you want to install Sierra but keep your data untouched, you can select 'Install OS X'. However, if you wish to delete all your data, then you can select Disk Utility to format the entire drive and wipe away all your data to reformat the internal drive first and then install macOS Sierra.

You now have a bootable copy of the macOS Sierra installer, and you can use it on multiple Macs to install the Mac OS. If you are familiar with the command line, you can opt to create a bootable drive using Terminal. For others, you can simply opt for reliable Mac hard drive recovery software like Recoverit and assist you in recovering your data as well from crashed systems in case of emergencies.

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