How Do I Format a USB or External Hard Drive?

Authored by: Support.com Tech Pro Team

Formatting a USB drive or an external hard drive for use with a Windows or Mac PC can be necessary for various reasons, including preparing the drive for storage, resolving disk errors, or changing the file system. On this page, you will find “quick start” guides to take you through the formatting process for USB drives and external hard drives for users of both Windows or Mac PCs.

Here's a “quick start” guide to help you format a USB or external hard drive on a Windows computer:

Important Note: Formatting a drive will erase all data on it, so make sure to back up any important data before proceeding.

Formatting USB or External Hard Drive Instructions (Windows PC)

Plug the USB drive or connect the external hard drive into an available USB port on your Windows PC.

Check Drive Compatibility

Ensure that the drive is compatible with your Windows operating system. Most Windows versions support the NTFS and exFAT file systems, but older versions might not fully support exFAT.

Backup Important Data

If there's any important data on the drive, back it up to another location. Formatting will erase all existing data.

Open File Explorer

Press the "Windows" key on your keyboard or click the Windows icon in the taskbar to open the Start menu. Type "File Explorer" into the search bar and press "Enter" to open File Explorer.

Select the Drive

In File Explorer, you'll see a list of drives and devices on the left sidebar under "This PC." Locate and select the drive you want to format.

Format the Drive

With the drive selected, click the "Manage" tab in the File Explorer ribbon (or right-click on the drive and select "Format" from the context menu).

Configure Format Options

A Format dialog box will appear. Here's how to configure the format settings:

Choose the file system format you want. For most cases, "NTFS" is a good choice as it provides better performance and security features. If you need compatibility with macOS or other operating systems, you can choose "exFAT."

Allocation Unit Size: Leave this at the default setting unless you have specific requirements.

Volume Label: Enter a name for the drive (choose something descriptive).

Quick Format: If you want a faster format (recommended for new drives or drives without known issues), keep this option checked. If you suspect the drive has errors, uncheck it for a more thorough format.

Start Formatting

Double-check your settings to ensure they're correct. Click the "Start" button in the Format dialog box. A warning message will appear, informing you that all data on the drive will be deleted. Confirm that you want to proceed.

Once the formatting is complete, you'll receive a notification that the format was successful. Click "OK" to close the dialog box.

Eject the Drive

To safely remove the drive, right-click on it in File Explorer and select "Eject" from the context menu.

Your USB drive or external hard drive is now formatted and ready for use with your Windows PC. Depending on the chosen format, it may also be compatible with other operating systems. Remember to regularly back up your data to prevent data loss in the future.

Here is a “quick start” guide for formatting a USB or external hard drive for a Mac computer:

Formatting a USB or external hard drive for a Mac computer is a common task that can be crucial for various reasons. 

Why Format a USB or External Hard Drive for Mac?

Compatibility: The most common reason to format a USB or external hard drive for a Mac is to ensure compatibility with macOS. Mac computers use a different file system compared to Windows, and formatting the drive ensures it can be read and written on a Mac without issues.

Performance Improvement: Formatting can also improve the performance of your device. Over time, drives can become cluttered with unnecessary data, leading to slower performance.

Data Security: When you're giving away or selling your external drive, formatting is essential to prevent the next user from accessing your personal data.

Error Fixing: If your drive has errors or has become corrupt, formatting can often be a simple solution to fix these issues.

Switching File Systems: You might need to switch between file systems (like from FAT32 to exFAT or HFS+) to meet specific requirements, such as file size limits or compatibility with other operating systems.

How to Format a USB or External Hard Drive for Mac:

Before You Begin

Backup Data: Ensure you have backed up any important data from the USB or external hard drive, as formatting will erase all data on the drive.

Power Supply: If you're formatting an external hard drive, ensure it's connected to a power source if required.

Step-by-Step Guide

Connect the Drive: Plug your USB or external hard drive into your Mac.

Open Disk Utility: You can find Disk Utility by searching in Spotlight or navigating through Finder > Applications > Utilities.

Select the Drive: In Disk Utility, you'll see a list of drives. Select the USB or external hard drive you want to format.

Choose ‘Erase’: Click on the ‘Erase’ button at the top of the Disk Utility window.

Set Format and Scheme:

Format: Choose a file system format.

For Mac-only use, select ‘Mac OS Extended (Journaled)’. For cross-platform use, select ‘exFAT’ (for larger file sizes) or ‘FAT32’ (for smaller file sizes but with a 4GB file size limit).

Scheme: Select ‘GUID Partition Map’ for newer Macs or ‘Master Boot Record’ for older ones. Enter a name for your formatted drive.

Erase and Format: Click ‘Erase’ to begin the formatting process. This may take a few minutes depending on the size and type of the drive.

Eject the Drive: Once the process is complete, eject the drive properly by right-clicking on its icon on the desktop and selecting ‘Eject’.

After Formatting

Time Machine Backup: If you're planning to use the drive for Time Machine backups, you can set it up in System Preferences > Time Machine.

Data Transfer: Transfer any data back onto the drive if needed.

Formatting a USB or external hard drive for your Windows or Mac PC ensures compatibility, optimizes performance, and helps in data management. By following the steps outlined above, you can easily format your drive for optimal use with either Windows or Mac computers. Always remember to backup important data before proceeding with formatting to avoid any data loss.

Contact Support.com: If you are still having trouble please refer to the step-by-step guides below or contact Support.com for personalized assistance.

1. Introduction: Format USB Drive

USB drives are great for carrying or backing up data and transferring data between devices. In order for the data to be read from a USB drive, the USB drive has to be formatted so that the computer or device is able to recognize it. Formatting a USB drive can also be performed when you wish to erase all contents contained on it. USB drives can be formatted with different file systems, such as NTFS, FAT, HFS, APFS, EXT, etc. The type of file system that is needed on your USB or external hard drive will vary depending on the type of device it is being plugged into or used with. Unless a device offers to format a USB drive to the necessary format when connected (if necessary), having a computer will be necessary in order to accomplish this process.

While most devices will alert you if you connect a USB drive with an incompatible file system that needs to be formatted, refer to your device's documentation for more information about what file systems are compatible with your device.

While USB drives may come in different physical forms, the process to format them is the same:

• USB flash drives
  

• USB external hard drives or solid state drives
  

2. Computer: OS Choice

To continue, we need to know what Operating System your computer is using.

There are 2 main Operating Systems for personal computers currently available, Microsoft Windows and Apple macOS.

Microsoft WindowsApple macOSMicrosoft Windows runs on computers produced by multiple companies, such as Lenovo, Asus, Dell, Toshiba, Hewlett Packard, Acer, and Sony.Apple is the only company that makes macOS computers.

3. Windows: Format USB Drive

Any and all data on the USB drive will be destroyed during this process. Make sure the drive is blank, or copy the data to a safe place before proceeding.

1. Insert a USB disk into your USB port.
2. Open Windows Explorer.
   

1. In the right-hand pane, locate your USB disk under This PC.
   

1. Using your right mouse button, right click on your USB disk. A menu will open up.
   

1. Select Format...
   

1. Select the File system you'd like the drive to have and type in a name for the Volume label.
   

1. Select Start.
   

1. A message will open, reminding you that any and all data will be lost. If you are sure this is okay, select OK.
   

1. Once the disk is done formatting, a message will open to tell you it is complete. Select OK.
   

4. macOS: Format USB Drive

Any and all data on the USB drive will be destroyed during this process. Make sure the drive is blank, or copy the data to a safe place before proceeding.

1. Insert a USB disk into your USB port.
2. macOS will recognize the disk and show its icon on the desktop.
   

1. Launch Disk Utility.
2. Select Search in the top-right corner.
   

1. type in "Disk Utility". Select the Disk Utility search result.
   

1. Select your USB Disk from the list on the left.
   

1. Select Erase at the top.
   

1. Type in a Name for the drive, then select a Format.
   

1. Format types to select from are shown below.
   

1. Select Erase.
   

1. A progress bar will open. Wait will the disk is formatted.
   

1. Once complete, select Done.
   

1. Quit Disk Utility. Select the Disk Utility menu at the top, then Quit Disk Utility.