Formatting a USB flash drive can change the file system to make it compatible with your computer's operating system, as well as fix any non-physical errors on the drive itself. Be aware that formatting a hard drive erases the drive's contents in the process.

Method 1: On Windows 10

1. Plug your USB flash drive into your computer.

2. Open Start . Click the Windows logo in the bottom-left corner of the screen, or press "⊞ Win" on your keyboard.

3. Open "File Explorer" . Click the file-shaped icon in the lower-left side of the Start window.

4. Click "This PC". It's on the left side of the File Explorer window.

5. Click your external flash drive's name. It's under the "Devices and drives" heading in the middle of the This PC window. Clicking the drive will select it.

6. Click the "Manage" tab. It's a menu item in the top-left side of the This PC window.

7. Click "Format". This flash drive-shaped icon is in the Manage toolbar near the top of the window. Clicking it opens the Format window for your external drive.

8. Click the "File System" box. It's below the "File System" heading near the top of the page. Doing so prompts a drop-down menu with the following options:
· NTFS - Use this for Windows-only drives.
· FAT32 - Works on Windows and Mac, but has a storage limit of 32 gigabytes with an individual file size of 4 gigabytes.
· exFAT (Recommended) - Use this for hard drives you plan on using with multiple devices (Mac, Windows, console, etc.). Similar to FAT32, but has no storage limit.

9. Select a format. Click the format you want to use to select it.
· If you've formatted your drive before, check the Quick Format box as well.

10. Click "Start", then click "OK". Doing so prompts Windows to begin formatting your drive.
· Your external hard drive's files will be erased during this process.

11. Click "OK" when prompted. Your external drive has now been reformatted to your selected file structure.

Method 2: On Mac

1.Plug your iDiskk flash drive into your computer.
· If you're using an iMac, you may find the USB ports on the side of your keyboard or on the back of the iMac's screen. · Not all Macs have USB ports. If you're using a newer Mac that doesn't come with USB ports, you'll need to use a USB-C ports.

2.Open the "Finder". It's the blue, face-shaped icon in the Dock.
· You can also just click the desktop.

3.Click "Go". This menu item is in the upper-left side of the screen.
· Click "Utilities". It's near the bottom of the Go drop-down menu.

4.Double-click "Disk Utility". You'll find this in the middle of the Utilities page.

5.Click your USB flash drive's name. You'll see it in the window on the left side of the Utilities window.

6.Click the "Erase" tab. It's at the top of the Disk Utility window.

7.Click the "Format" drop-down box. It's in the middle of the page. A drop-down menu will appear with the following format options:
· Mac OS Extended (Journaled) - The default Mac format. Only works on Mac.
·Mac OS Extended (Journaled, Encrypted) - Encrypted version of the default Mac format.
· Mac OS Extended (Case-sensitive, Journaled) - Version of the default Mac format that treats files with the same name differently if there are case differences (e.g., "file.txt" and "File.txt").
· Mac OS Extended (Case-sensitive, Journaled, Encrypted) - A combination of the three above formatting options for the Mac format.
· MS-DOS (FAT) - Works on both Windows and Mac computers, but has file size limit of 4 gigabytes.
· ExFAT (Recommended) - Works on both Windows and Mac computers. Has no storage limit.

8.Select a format. Click a format you want to use.

9.Click "Erase", then click "Erase" when prompted. Doing so will cause your Mac to begin erasing and reformatting your usb flash drive. Once it finishes, your drive will be reformatted.