If you want to completely format an external hard drive, the process is pretty straightforward, but there is one important thing to understand first: formatting erases the data stored on the drive. If you have photos, videos, documents, backups, or other files you still need, copy them somewhere safe before you begin.
The exact steps depend on whether you are using Windows, macOS, or Linux.
Quick Steps
- To completely format an external hard drive on Windows, connect it, open File Explorer, right-click the drive, select Format, choose a file system, and start the process.
- On macOS, connect the drive, open Disk Utility, select the physical external drive, click Erase, choose the appropriate format and scheme, and confirm.
- On Linux, connect the drive, open your disk-management utility, select the external drive, choose Format Partition, select a file system, and apply the changes.
- Before formatting on any OS, verify the correct drive and back up anything important because formatting removes the existing file structure and makes the stored data inaccessible through normal use.
- For a drive that needs to work across Windows and Mac, exFAT is usually the most practical choice.
Before formatting, disconnect other unnecessary external storage devices if possible. This makes it easier to identify the correct drive and reduces the chance of accidentally formatting the wrong disk.
You should also decide how you plan to use the drive. NTFS is a strong choice for Windows-only use. APFS works well for modern Mac use. exFAT is a convenient option when you regularly move the drive between Windows and macOS.
Remember that formatting is different from simply deleting files. Deleting files removes their directory references, while formatting creates a new file system structure for the partition.
If your goal involves securely disposing of sensitive data, ordinary formatting may not be enough.
Format an External Hard Drive on Windows
Step 1: Connect the External Hard Drive
Connect the external hard drive to your Windows computer using its USB cable. Give Windows a few moments to recognize it. You should normally hear the connection sound and see the drive appear in File Explorer under This PC.
Open File Explorer and look at the available drives. Pay close attention to the drive letter and storage capacity. For example, if your external drive is labeled Backup and has a capacity of 1 TB, use those details to identify it. Do not continue until you are confident that you have selected the correct drive.
Step 2: Open the Format Window
In File Explorer, go to This PC, locate the external hard drive, and right-click it. Select Format from the context menu.
Windows will display a formatting window containing options such as Capacity, File system, Allocation unit size, and Volume label. You can give the drive a new name in the Volume label field if you want.
Step 3: Choose the File System
Select the file system based on how you plan to use the drive. Choose NTFS if the drive will primarily be used with Windows. Choose exFAT if you want broad compatibility between Windows and macOS. Avoid choosing a file system simply because it appears first in the menu.
For most people who regularly switch between Windows and Mac, exFAT is the easiest choice. Leave Allocation unit size at its default setting unless you have a specific technical reason to change it.
Step 4: Start the Format
Check the formatting options carefully, then click Start. Windows will warn you that formatting will erase the data on the drive. Read the warning and make sure you have backed up anything important.
Click OK to proceed. Windows will format the selected partition. Once the operation finishes, the drive should appear with the new file system and an empty directory structure.
Step 5: Verify the Drive
Open the newly formatted drive in File Explorer. It should contain no personal files unless Windows created system-related information. Right-click the drive, select Properties, and check the File system field to confirm that the format is correct.
If the drive still contains unexpected partitions or you specifically want to restructure the entire disk, use Disk Management rather than relying only on the File Explorer Format command. Be especially careful because disk-level operations can affect multiple partitions.
Format an External Hard Drive on macOS
Step 6: Connect the Drive and Open Disk Utility
Connect the external hard drive to your Mac. Then open Disk Utility by pressing Command + Space, typing Disk Utility, and opening the application.
In Disk Utility, select View > Show All Devices. This is important because it lets you see the physical external drive and the volumes or partitions underneath it.
Step 7: Select the Correct Physical Drive
Look at the left sidebar and identify your external hard drive using its name and capacity. Select the physical device rather than accidentally selecting your Mac’s internal storage.
Take a moment here. Selecting the wrong device can cause serious data loss, so verify the drive before moving forward.
Step 8: Click Erase
With the correct external drive selected, click Erase at the top of Disk Utility. Enter a name for the drive and choose a Format.
For use with modern Macs, APFS is generally appropriate. For compatibility between Windows and macOS, select exFAT. If you have a specific older Mac compatibility requirement, another available Mac format may be appropriate.
Step 9: Select the Scheme and Confirm
If Disk Utility provides a Scheme option, GUID Partition Map is generally the appropriate choice for modern computers and external drives.
Review the selected device, format, and scheme carefully. Click Erase to begin. Disk Utility will remove the existing volume structure and create the new one. When the operation finishes, click Done.
Step 10: Check the Formatted Drive
The newly formatted drive should appear in Finder. Open it and confirm that the previous files are no longer visible. You can also return to Disk Utility to confirm the selected file system.
If you intended to erase the entire physical disk but still see multiple partitions, you may need to repeat the process from the physical device level rather than formatting only one volume.
Format an External Hard Drive on Linux
Step 11: Connect the External Drive
Connect the external hard drive to your Linux computer and wait for the system to recognize it. Many Linux distributions automatically mount external drives and display them in the file manager.
Before formatting, identify the drive using its storage capacity, device name, and partition information. This is especially important on Linux because disk operations can be performed directly against storage devices.
Step 12: Open the Disk Utility
Many Linux distributions provide a graphical disk-management application, often called Disks. Open your application menu and search for Disks or your distribution’s disk utility.
Select the external hard drive from the device list. Confirm its capacity and make sure it is not your operating system’s internal disk.
Step 13: Unmount the Partition
If the external drive is currently mounted, unmount the partition before formatting it. In Disk Utility, select the relevant partition and use the Unmount option.
This prevents the system from actively using the partition while you modify its file system.
Step 14: Format the Partition
Select the partition’s settings and choose the option to Format Partition. Linux may present several file-system choices. Choose exFAT for broad Windows and macOS compatibility, or choose a Linux-oriented file system such as ext4 if the drive will mainly be used with Linux.
Follow the on-screen instructions and confirm the operation. Depending on your Linux distribution, you may need to authenticate with your administrator password before the formatting operation can proceed.
Step 15: Mount and Verify the Drive
After formatting finishes, mount the newly formatted partition. Open your file manager and check that the drive appears correctly.
Create a small test folder or file to verify that you can write to the drive. Then check the drive’s properties to confirm that the expected file system is being used.
Important Tips Before Completely Formatting
The biggest mistake beginners make is formatting the wrong drive. Always compare the drive’s capacity and name before clicking Format or Erase. If you have several external drives connected, disconnect the ones you do not need.
If you are formatting the drive because it has errors, formatting may not solve an underlying hardware problem. Repeated disconnections, clicking sounds, extremely slow transfers, or frequent file corruption can indicate a failing drive.
Also, remember that a normal format should not be treated as a guaranteed method for securely destroying confidential information.
If you are permanently disposing of a drive containing sensitive information, use an appropriate secure-erasure or drive sanitization method for the specific storage technology.
Faqs
Does completely formatting an external hard drive delete everything?
A normal format removes the existing file-system structure and makes the previous files inaccessible through ordinary use. However, it does not necessarily mean every underlying data sector has been securely overwritten.
Which format is best for Windows and Mac?
exFAT is generally the easiest choice when you need to use the same external hard drive with both Windows and macOS.
Should I choose NTFS or exFAT?
Choose NTFS when Windows is your primary operating system and you want Windows-oriented features. Choose exFAT when cross-platform compatibility is more important.
Will formatting fix an external hard drive?
Formatting can resolve certain file-system problems, but it cannot repair physical hardware failure. If the drive is making unusual noises, disconnecting frequently, or reporting serious hardware errors, formatting may not be the right solution.
Can I format an external hard drive without losing data?
Not if your goal is to completely format the existing file system. Back up your files first, then format the drive.
What should I do if Windows does not show my external hard drive?
Check the USB connection and try another port or cable. If the drive still does not appear in File Explorer, open Disk Management and see whether Windows detects the physical disk there. If it appears without a usable volume, additional disk-management steps may be necessary.
Can I use the same external drive on Windows, Mac, and Linux?
Yes. exFAT is commonly used when you want one drive to work across these operating systems. However, support and permissions can vary depending on the Linux distribution and configuration.