Format Large USB Drive As FAT16 In Windows

Format Large USB Drive As FAT16:

Maximum Volume and File Sizes for FAT16/FAT32/exFAT:
FAT16: Max volume size: 4 GB, Max file size: 2 GB.
FAT32: Max volume size: 2 TB, Max file size: 4 GB.
exFAT: Max volume size: 128 PB, Max file size: 16 EB.

If your USB flash drive partition size is larger than 4 GB, you need to resize it to 4 GB to format it as FAT16.

Steps to follow:

We will use DiskPart to Resize USB partition to 4 GB.
Warning: Back up ALL data on the USB as it will be completely erased by the formatting tool!

For each of the following commands, press ENTER on your keyboard after typing the command (denoted in this font).

1. Insert the USB to be formatted as FAT16.

2. Open a Command Prompt window as administrator.
   - On Windows XP: Log in as administrator. Press Windows key + R to open Run. Type cmd to open.
   - On Windows Vista and newer: Press the Windows key. Type cmd and wait for the option to appear. Right-click and select Run as Administrator. Click Yes when prompted by UAC.

3. Type DISKPART in this window to launch Microsoft DiskPart tool.

4. In the window, type: list disk

5. An example output is shown below:

DISKPART> list disk
 
  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          238 GB  1024 KB        *
  Disk 1    Online         7538 MB      0 B
6. In the above example, the USB drive is Disk 1 (7538 MB). This may NOT be in your case! Identify the disk # by the size. If you are unsure, select one of the disks with the following command (substitute # with the disk number): SELECT DISK # then type DETAIL DISK to see the disk name and assigned drive letters.

7. Select the correct disk by typing SELECT DISK # to select it. An example output is shown below:

DISKPART> select disk 1

Disk 1 is now the selected disk.

8. Type LIST PARTITION to double-check that you have selected the right disk. An example output is shown below:

DISKPART> list partition

  Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
  Partition 1    Primary           7538 MB  1024 KB
9. Once you are sure you have selected the right disk, type CLEAN to delete all existing partition information from the selected disk. WARNING: THIS IMMEDIATELY DELETES ALL PARTITIONS ON THAT DISK!

DISKPART> clean

DiskPart succeeded in cleaning the disk.
10. To create a 4000 MB (4 GB) partition on the now-erased USB, type CREATE PARTITION PRIMARY SIZE=4000 to create it.

DISKPART> create partition primary size=4000

DiskPart succeeded in creating the specified partition.
11. Then, we will make this partition active by typing ACTIVE.

DISKPART> active

DiskPart marked the current partition as active.
12. Type ASSIGN to assign a drive letter to the drive.

DISKPART> assign

DiskPart successfully assigned the drive letter or mount point.
13. Type EXIT to close DiskPart. The Command Prompt window should remain open.

14. If a window pops up asking you to format the disk, you can follow the prompts to format the drive via the GUI (remember to select "FAT", NOT "FAT32" under "File system"!) and skip the remaining steps of this tutorial (you may type EXIT to close the Command Prompt window). Otherwise, continue below.

15. Now, we will format this newly-created partition as FAT16. First, open My Computer/Computer to see the drive letter of the USB drive.

16. Go back to the Command Prompt window. Type FORMAT X: /FS:FAT /Q where X is the drive letter of your USB, then type Y to confirm. This may take several minutes to complete.

17. The USB drive is now formatted as FAT16. Type EXIT to close the Command Prompt window.

If you would now like to return your USB drive partition back to FAT32 (or NTFS) to allow you to use the USB drive's full capacity again, just repeat the steps above, except at Step 10, where you will now type CREATE PARTITION PRIMARY (without the SIZE parameter) to create a single partition spanning the entire disk.

Did you found the above guide useful? If so, share it with your friends. Comments on how to improve the guide are welcome below.

Improved and extended steps from https://www.instructables.com/id/Format-USB-Flash-Drive-to-FATFAT16-not-FAT32/.