How to Boot from External Hard Drive?

Theo Lucia

Dec 16, 2024 • Filed to: Answer Hard Drive Problems • Proven solutions

If you have to change the device priority list, then you should know how to boot Windows or Mac from the external hard drive. It is the same as choosing an internal drive to be a bootable media. Not every drive can be booted. But by making appropriate changes to the drive boot mechanism, you can make any drive bootable.

The article is all about how to make external hard drive bootable on Windows and Mac computers.The detailed steps are listed clearly for your reference. You can follow to boot the disk.

Reasons for Booting an External Hard Drive

Some people choose to boot their internal hard disk, while others prefer to boot the an external hard drive. The following are reasons why some choose to make their external hard drive bootable.

1. When Windows 10 fails to boot from the internal hard drive. You need an external bootable hard drive for carrying out a boot mechanism. You can change the priority list from BIOS.
2. Failure of external media can be due to hard drive corruption, bad sectors, or corrupted partitions containing the BIOS.
3. Virus or malware attack on the drive containing the BIOS information.
4. In case you are not able to access your device, you can sue the external bootable media on other devices by using your own operating system anywhere anytime.

And before booting up an external hard drive on Windows or Mac, you need to set some essential configurations before carrying out the booting methods.

Setting up Your External Hard Drive

In this section, you would get the solution for booting from an external hard drive. This explains all the essentials for setting up the external hard drive to become bootable media.

1 Figure out your computer’s BIOS key on Windows.

For setting up the external hard drive to become bootable, the first step is to figure out the BIOS key on Windows. As for the device, for setting into BIOS settings, we usually press and hold F12. But in the case of Windows, here are the steps:

1. Launch the search engine. Be it any search engine e.g. google.
2. In the search box, type the computer’s manufacturer, the name of the model, and the phrase bios key. Click enter to continue.
3. Related to your search, the browser will show up with certain options. Select the BIOS key that is compatible with your device.
4. Else you can check the device’s manual to search for the BIOS key.

2 Attach the external hard drive to your computer.

In order to make an external drive bootable, it should be kept in mind that the drive should be in constant and appropriate connection with the device. Use a USB cable or free USB port to attach the hard drive with the device. The external hard drive carries an indicator light that either blinks or stabilize when in sound connection with the device. For Mac devices, you would need a USB or thunderbolt 3 adapter.

3 Format the hard drive if necessary.

As soon as your external hard drive is in an inappropriate connection with your device, make sure the drive should not carry any extra or non-functional data that would otherwise interfere with the boot mechanism. Moreover, if the hard drive is not compatible with the device i.e. the file format on the drive is not compatible, your device won’t be able to read it. In this regard, you can go for formatting the drive into a compatible file system. NTFS for Windows and Mac OS extended are preferred file systems. An all-rounder i.e. exFAT file system can be used for both, Windows and Mac devices. Once the drive and device are compatible, next you have to reformat your drive according to the data going to be stored in it.

Formating hard drive in a safe mode is very important and essential. If you forget to back up your files and folders and lose all the data accidentally, you can use Wondershare Recoverit to recover all your lost data. Only through three simple steps, your precious files will be back.

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Step 1. Launch the Program

Once you have downloaded and installed Recoverit, open the program on your computer and navigate to the Hard Drives and Locations section.

Step 2. Initiate the Drive Scan

Identify the disk containing the crucial data you wish to recover. Choose the drive and initiate the file search process. Initially, a quick scan will be performed, followed by a more thorough deep scan to locate additional lost data on the drive.

Step 3. Preview and Retrieve

Allow the scanning to finish. Review the identified files for recovery, select the ones you need, click on Recover, and specify a location to store the recovered data.

4 Make sure you have an item from which to boot.

While in the process to boot the external hard drive. There are some requirements. You need a disc image or ISO file present on the hard drive. Only then you would be able to boot the drive. An empty drive is not bootable. Apart from the ISO (disc image) files, the drive can also carry file history backup for Windows or Time Machine backup in case of Mac that makes the drive eligible for booting.

5 Place the boot file on the external hard drive.

It is not necessary that an external hard drive should itself carry the ISO files to be booted, rather you can drag-drop the ISO files into the external hard drive window. If you are using Windows 10 installation tool for creating bootable media, you can skip this step.

6 Make the external hard drive bootable.

Prior to booting the external hard drive, it is important to at least once view the bootable item. For this, you can sue the command prompt in case of Windows or terminal for the Mac devices. In case, if you care to sing Linux to burn ISO files on the external drive, then the drive would be booted in the process.

Booting from an External Hard Drive on Windows

Every operating system carries its own set of requirements when it comes to boot the external hard drive and then to boot the OS from that external media. So as the case with Windows. This section will tell how to boot from an external hard drive Windows 10. Here are the steps:

Step 1: Start the process by connecting the external hard drive with the device appropriately. Make sure that your device recognizes the external hard drive.

Step 2: In the Windows main menu, click the option of power to restart your device.

Step 3: While your device is in process of restarting, press the BIOS key repeatedly.

Step 4: Your device with a restart in and the BIOS menu will appear on the screen.

Step 5: Select the option of boot order from the list.

Step 6: In the next window, select your hard drive in the boot order list. In some cases, the system only allows the USB attached devices to be recognized in the boot order. So make sure that your drive is only USB storage.

Step 7: Now drag your external hard drive to the top of the list i.e. boot order. Save changes and exit BIOS.

Step 8: Now run any on-screen prompt to open, install, or set the program for the external hard drive. In case you already have an OS installed for the external hard drive, then once you are done with the BIOS setting, the OS will open.

Booting from an External Hard Drive on Mac

Booting from an external hard drive on Mac also has a set of instructions. Below mentioned are some of them, just follow the steps and boot from the external hard drive on Mac.

Step 1: Initiate the process by attaching the external hard drive with your Mac device, make sure the connection is appropriate for that the device could recognize the external hard drive.

Step 2: In Mac main menu, select the option of power, and in the pop up select the option of the restart. Your device will restart.

Step 3: As soon as the screen turns off, press the BIOS key destined for Mac devices. Press and hold the BIOS key until the startup manager window appears on the screen.

Step 4: From the menu, select the external hard drive and confirm your selection. This will mark the external hard drive as the booting media for your operating system.

Step 5: Once the drive is selected, exit the startup manager and follow all the on-screen prompt instructions to open, install, and set up the program. In case you already have the operating system, then as soon as you set the priority setting, the OS will open.

Final Words

Hence, using an internal hard drive for booting the operating system via it is a common practice. Mostly C drive is the partition that carries all the system files and is destined to boot the OS. But at times, when the operating system fails to boot due to any technical or physical issue to hard drive i.e. bad sector, corrupted partition, and physical damage to hard drive during a disaster, or whole hard drive corruption due to any virus or malware attack. All these situations won’t allow the operating system to work and leaves your device in a non-functional state. In this regard, using an external hard drive for booting the operating system on your device is recommended. This article is all about the details of two important questions i.e. how to make an external hard drive bootable and how to boot from the external hard drive. This article further explains the process for booting from an external hard drive on Windows and Mac separately.