Formatting a USB drive is a common task that allows you to wipe the drive clean and start fresh. However, sometimes you may run into issues where your USB drive cannot be formatted due to errors. There are several potential causes for this problem and a variety of solutions you can try to get your USB working again.
In this comprehensive guide, we will cover the most common reasons a USB drive may not format properly and walk through various troubleshooting methods step-by-step. Read on to learn how to diagnose and fix a USB that cannot be formatted in Windows, Mac OS, or Linux operating systems.
What Does “USB Cannot Be Formatted” Error Mean?
When you attempt to format a USB drive and receive an error stating the device “cannot be formatted”, it means the operating system was unable to complete the formatting process.
This is typically due to data corruption, physical damage, or issues with the file system on the USB drive. The operating system cannot overwrite the existing data structures on the drive to create a new blank file system.
Some common error messages you may see include:
– “Windows was unable to complete the format”
– “The disk cannot be formatted”
– “Formatting did not complete successfully”
– “Input/output error”
The specific error message depends on the operating system, but they all indicate the OS could not properly format the USB device.
Why Won’t a USB Drive Format?
There are several potential reasons why a USB may fail to format properly:
Corrupted File System
The file system on the USB, which organizes the data into files and folders, may have become corrupted. This can happen if the USB was removed improperly while files were still being written or if it was exposed to an unexpected power loss. Corruption prevents the operating system from being able to overwrite the file system.
Bad Sectors
Bad sectors are areas on the physical USB drive that can no longer reliably store data due to damage or manufacturing defects. If formatting tries to write to these bad sectors, it will fail.
Physical Damage
Dropping the USB or exposing it to moisture can physically damage the drive and make it unable to be reformatted. This is more common with cheap USB drives.
Write Protection
Some USB drives have a write protection switch to prevent accidentally deleting or overwriting data. If this switch is enabled, it will block formatting the drive.
Insufficient Permissions
To format a drive, users need administrative privileges. On Linux or Mac, you may get errors if trying to format a USB as a standard user without admin rights.
Outdated Firmware
USB drives contain firmware that operates at the hardware level. Outdated or buggy firmware can sometimes cause formatting issues.
Bad USB Port
Problems with the USB port you are connecting to, including loose connections or damaged ports, can interfere with formatting.
How to Fix USB Unable to Format in Windows
If your USB drive cannot be formatted on a Windows PC, try these troubleshooting steps:
Step 1: Use Disk Management
Disk Management is a built-in Windows tool for managing connected drives. You may be able to format drives here that fail when trying to format in File Explorer.
To open Disk Management:
– Press Windows key + R to open the Run dialog
– Type “diskmgmt.msc” and click OK
– This opens the Disk Management utility
– Locate your USB drive in the list
– Right click on it and choose “Format”
– Try quickly reformatting as FAT32 or NTFS
This may resolve any software issues getting in the way of formatting.
Step 2: Use DiskPart
DiskPart is another command line disk formatting utility included in Windows. To try formatting with DiskPart:
– Press Windows key + R to open the Run dialog
– Type “diskpart” and press Enter
– Type “list disk” and press Enter to show connected drives
– Type “select disk X” where X is your USB drive number
– Type “clean” to delete all existing partitions
– Type “create partition primary” to create a new primary partition
– Type “format fs=fat32 quick” to format as FAT32
– Type “exit” when done
Running these DiskPart commands should force a reformat of the USB drive and resolve many errors.
Step 3: Try a Different USB Port
If you are still unable to format the USB drive, try unplugging it and switching to a different USB port on your computer.
The port you are currently using to connect the drive may be damaged or not functioning properly. Try every USB port available to see if the drive can be formatted from another one.
Step 4: Disable USB Write Protection
Some USB drives have a physical write protection switch on the housing. This prevents formatting or writing to the drive when enabled.
Double check your USB drive for a small slider switch. Slide it to the opposite position to disable write protection so the drive can be formatted.
Step 5: Update your USB Controller
Outdated drivers for your USB controller or ports can sometimes lead to formatting issues.
You can update your drivers in Device Manager:
– Right click the Start button or press Windows + X
– Choose Device Manager
– Expand the Universal Serial Bus controllers section
– Right click each USB device and select Update driver
– If updates are available, install them and restart your PC
This will ensure your USB controllers have the latest software to properly communicate with your drive.
Step 6: Check for Bad Sectors
Extensive bad sectors can prevent a USB from being able to format. You can scan for bad sectors using the built-in Windows tool Check Disk:
– Open a Command Prompt as administrator
– Type “chkdsk x: /f” where x is your flash drive letter
– This will scan and repair any bad sectors
If chkdsk is unable to fix the bad sectors, it confirms your drive has physical damage that requires replacement.
Step 7: Low-Level Format
Low-level formatting completely erases and resets your USB flash drive at a hardware level. This can fix hardware issues and file system errors.
You’ll need to use a third-party low-level format tool since Windows does not include this feature. Some options include:
– HDD Low Level Format Tool
– Low Level Format Tool
– HP USB Disk Storage Format Tool
Just make sure you backup all important data first, as low-level formatting will erase everything.
How to Fix a USB Unable to Format on Mac
If your USB drive won’t format properly on a Mac, these tips can help:
Step 1: Try Disk Utility
Disk Utility is included with Mac OS and provides options for formatting drives. Using this may bypass any software issues interfering with formatting.
To try formatting with Disk Utility:
– Launch Disk Utility located in Applications > Utilities
– Select your USB drive in the left panel
– Click Erase across the top menu bar
– Rename the drive if desired
– Select a format like MS-DOS (FAT) or APFS
– Click Erase to reformat the drive
Step 2: Use Terminal Disk Formatting Commands
The Terminal app allows you to enter disk formatting commands at a low level. This can format USB drives even when Disk Utility fails.
To try formatting the USB drive from Terminal:
– Launch the Terminal app from Applications > Utilities
– Type “diskutil list” and locate your USB drive identifier (such as disk2)
– Type “diskutil unmountDisk /dev/diskN” where N is your drive number
– Type “sudo newfs_msdos -F 16 /dev/rdiskN” to quickly format as FAT16
– Type “diskutil eject /dev/diskN” to safely eject the drive
Step 3: Try a Different USB Port
Just like on Windows, a damaged or malfunctioning USB port could prevent properly formatting a drive. Try unplugging your USB and plugging it into another port on your Mac.
Step 4: Reset NVRAM on Older Macs
On older Macs before 2018, you can try resetting the NVRAM to resolve any USB issues:
– Shut down your Mac
– Turn it back on and immediately press Command + Option + P + R
– Hold the keys until you hear the Mac restart sound a second time
– Let go and the NVRAM will be reset
Then try formatting the USB again.
Step 5: Update Your USB Drivers
Having outdated drivers for your Mac’s USB ports can interrupt communication with connected USB drives.
You can update your USB drivers by:
– Going to the Apple menu > About this Mac
– Clicking System Report
– Selecting Software in the sidebar
– Making sure you have the latest USB drivers under the Extensions section
Step 6: Check for Physical Damage
As a last resort, inspect your USB drive closely for any signs of physical damage. Look for dents, cracks, broken pieces, or exposed circuitry. Water damage or a short circuit can prevent properly formatting the drive.
If the drive has any physical damage, you will likely need to replace it.
How to Fix a USB Unable to Format in Linux
On Linux distributions, follow these steps when a USB won’t format:
Step 1: Use GParted to Format
GParted is a free partition editor for Linux that can often format drives the Linux Disk Utility struggles with.
To install and run GParted:
– Install with your package manager, e.g. sudo apt install gparted
– Launch GParted, either from your app menu or the command gparted
– Select your USB drive in the top right corner
– Go to Device > Create Partition Table
– This will delete any existing partitions
– Add a new partition with the format like FAT32 or ext4
– Click the checkmark icon to apply changes and reformat
Step 2: Format from the Command Line
The command line provides low-level disk access and more flexible formatting options.
To format a USB drive from Terminal:
– Use fdisk to delete existing partitions – sudo fdisk /dev/sdX
– Create a new DOS partition – n, p, 1, enter, enter
– Write and exit fdisk – w
– Create FAT32 filesystem – sudo mkfs.vfat /dev/sdX1
Replace sdX with your actual USB drive name.
Step 3: Disable Write Protection
Some USB drives have physical write protect switches. Switch this to the off position if your drive has one.
You can also check for software write protection flags using:
– lsblk –output NAME,RO
– This will list all drives and whether they are read-only (RO)
– Set a drive to read/write with – sudo blockdev –setrw /dev/sdX
Step 4: Update USB Drivers
Updating the USB controller drivers may resolve formatting issues:
– Determine your USB controller – lsusb
– Update its driver through your package manager
– For example: sudo apt update linux-image-generic
Step 5: Low-Level Format USB Drive
For extensive corruption, a low-level block device format may be required:
– Backup data and unmount the drive
– Install util-linux – sudo apt install util-linux
– Low level format – sudo dd if=/dev/zero of=/dev/sdX bs=512 count=1
– Create new partition table – sudo fdisk /dev/sdX
This will completely reset your USB flash drive at a hardware level if all else fails.
Tips to Avoid “USB Unable to Format” Errors
Follow these tips to prevent formatting issues when using USB drives:
– Always eject properly before unplugging the USB
– Don’t remove flash drives during writes – this corrupts data
– Handle drives gently and avoid physical damage
– Keep USB ports clear of dust and debris
– Only store important data in one place, not just on a USB drive
– When disk issues occur, reformat the drive instead of continuing to use it
Catching and troubleshooting problems early can often resolve minor corruption before it leads to unformattable drives.
When to Replace a USB Drive
If you still cannot format your USB drive after trying every troubleshooting step, the drive likely has irreparable physical damage. At that point, it is best to:
– Backup any retrievable data off the broken USB drive
– Obtain a new USB drive
– Copy your files to the new USB
Damaged drives will continue causing errors and become less reliable over time. Replacement is the safest option when low-level formatting cannot repair a USB.
Conclusion
While a USB drive failing to format can be frustrating, the problem can usually be resolved with some dedicated troubleshooting. Run through these advanced formatting techniques, port changes, software fixes, and physical inspections until your USB successfully reformats.
In rare cases of physical damage beyond repair, the USB will need replacement. Fortunately, flash drives have become inexpensive enough that replacing a damaged drive is an affordable last resort.
With the steps provided in this guide, you now have an effective toolkit to bring your unformattable USB drive back to reliable, fully-functioning status.