By Bryce / Last Updated May 6, 2023

Unable to format to FAT32 for USB drive

You may choose to format your USB drive like USB flash drive or SD card to FAT32 file system, as FAT32 has great compatibility – it can be supported by different operating systems including Windows OS and Mac OS and various electronic devices. But you’ll find that you can’t format to FAT32 for USB drive out of different reasons. 

☞ The partition that you need to format is larger than 32GB. Windows will not allow you to format partition beyond 32GB to FAT32. If you format the partition in File Explorer, you’ll find that there is no FAT32 option in the Format window. If you format it via Diskpart, you’ll get “The volume size is too big” error.

☞ The partition need formatting to FAT32 is not the first primary partition on a removable disk. Windows recognizes only the first primary partition on removable devices like USB flash drive, thus you can’t format the partition except for the first one on USB flash drive or SD card.

Unexpected error

☞ The USB drive is write-protected. When USB drive is in read-only mode, you’ll not allowed to make any write operation to it. Thus, you are unable to format write-protected USB drive.

write protected

Workable solutions for can’t format to FAT32

For specific situations, different solutions will be presented in detail to assist you to solve format to FAT32 failure for USB drive.

► Turn to third-party professional USB format software

If you need to format large partition, such 64GB or 128GB partition to FAT32 or format the second partition on SD card/USB flash drive, you can turn to AOMEI Partition Assistant Standard, a comprehensive and all-round USB FAT32 format tool for Windows operating system. It can help you to complete these operations quickly and simply. Free download it and have a look at how it works (Take formatting large partition to FAT32 as an example).

Download Freeware Win 11/10/8.1/8/7/XP
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Step 1. Install and run it. Right-click the partition needs to be formatted to FAT32 and choose “Format Partition”.

Format Partitoin

Step 2. It will pop up a small window, choose FAT32 among displayed file systems and click “OK”. You are allowed to change cluster size of this partition and add partition label to it as well.

Fat32 128gb Usb

Step 3. Return to the main console and you can review the operation. Please click “Apply” > “Proceed” after confirmation.


✐ Notes:
✔ If the partition going to be formatted is NTFS file system, you can use AOMEI Partition Assistant Standard to convert it to FAT32 without data loss.
✔ For enjoying more functions like recovering lost partition on external hard drive, SD card, USB flash drive, migrating Windows 10 or 11 from HDD to SSD, and so on, it is recommended to upgrade to a Professional version.

► Remove write protection from USB drive

As mentioned above, you can’t format read-only USB drive to FAT32 file system. If you need to do so, you can remove write protection from it. Here offers you some solutions.

Way 1. Clear readonly attributes using Diskpart

1. Open Run dialogue by pressing Windows+R simultaneously.

2. Input “diskpart” and hit Enter key.

3. Type the following command and hit Enter after each command.

▪ list disk
▪ select disk n
▪ attributes disk clear readonly

Attributes Disk Clear Readonly

Way 2. Disable write protection in Registry Editor

1. In Run box, type “regedit” and press “Enter” key.

2. Go to the path given below:


3. Right click the WriteProtect and change the value from 1 to 0. Then, click “OK” to disable read only for your USB drive.

Way 3. Adjust Windows local group policy

1. In the Run dialogue, input “gpedit.msc” and hit “Enter” key.

2. In the Windows local group policy editor window, navigate to:

Computer Configuration > Administrative Template>System > Removable Storage Access.

3. Disable “Removable Disks: Deny execute access”, “Removable Disks: Deny read access” and “Removable Disks: Deny write access”.

After removing write protection, you will be able to format USB drive to FAT32 or other file system.


If you can’t format to FAT32, you should figure out the reason for the issue at first. If the partition is too large or the partition is on SD card/USB flash drive but not the first partition, turn to AOMEI Partition Assistant Standard to format the partition with FAT32 file system immediately. If the USB dive is write-protected, change its read-only status to normal firstly. Then, you can use Windows built-in tools or AOMEI Partition Assistant Standard to format it.