Formatting USB flash drives

IMPORTANT: Before following any instructions on this page, back up anything currently on the flash drive as the entire drive will be erased.

Windows

1. Open a command prompt window in administrator mode:
   1. Search the start menu for "command prompt".
   2. Right-click on it and select "Run as administrator".
2. Use the diskpart tool to convert the drive to GPT:
   1. Type diskpart and press enter.
   2. Enter list disk. Note the disk number of the USB flash drive.
   3. Enter select disk X, replacing X with the disk number of the USB flash drive. Double-check the number is correct, as specifying the wrong number can erase your hard drive or another connected disk.
   4. Enter clean to clear the disk.
   5. Enter convert gpt to change the drive's partition table to GPT.
   6. Enter exit to close diskpart and then close the command prompt window.
3. Use the Disk Management tool to create a FAT32 partition:
   1. Right-click on the start button.
   2. Select Disk Management.
   3. Find the USB drive in the list in the bottom pane.
   4. Right-click the unallocated space and click New Simple Volume
      
   5. Click Next to start the volume wizard.
   6. Leave the default volume size and click Next.
   7. Leave the default drive letter and click Next.
   8. Set the file system to FAT32.
   9. Set the allocation unit size to Default.
   10. Enter any volume label.
   11. Click Next.
       
   12. Click Finish to create the partition.
   13. Wait for it to complete. The volume name and letter will appear on the partition block when it is created.

macOS

1. Open Disk Utility from Launchpad or /Applications/Utilities.
2. Click View > Show All Devices.
   
3. Select the USB drive (the root item, not the single partition) from the left sidebar and make sure it shows up in the right pane.
   
4. Click Erase from the top toolbar.
5. Enter any name.
6. Set the format to MS-DOS (FAT).
7. Set the scheme to GUID Partition Map.
   
8. Click Erase.

For more information, see the Disk Utility User Guide.

Ubuntu

These instructions assume the GNOME Disk Utility is installed.

1. Open Disk Utility.
2. Select the flash drive from the left sidebar.
3. Click the menu (3 dots) button at the top right.
4. Erase the entire drive:
   1. Click Format.
   2. Set Erase to Quick.
   3. Set Partitioning to GPT.
   4. Click Format.
5. When formatting completes, select the empty space under Volumes in the right pane.
6. Create a FAT32 partition:
   1. Click the plus button under the volume map.
   2. Set Erase to Quick.
   3. Set Type to FAT.
   4. Enter any name.
   5. Click Format.