By Bryce / Last Updated July 22, 2019

Why format USB flash drive?

USB flash drive is a kind of popular portable storage device, which can be used to back up or transfer data or as a bootable device. In general, formatting USB flash drive is out of these three causes:

  • The USB flash drive is formatted with FAT32 but you need to store individual large file on it.

  • The file system of the drive is incompatible with the operating system with which it will work.

  • The drive is without file system. You need to format it with certain file system before using it.

Need a great flash drive formatter

In many case, you can format USB flash drive with wanted file system within Disk Management by following the steps given below: Insert USB flash drive into computer and ensure that it can be detected. > Open Disk Management; right click the flash drive partition that you want to format and choose “Format…” > “Choose a proper one from listed file system” and click “OK”.

However, when you try to format 64GB or 128GB USB flash drive partition to FAT32 via Disk Management, you’ll find that there is no FAT32 option available. When you try to format the second partition on the USB flash drive, you’ll be prompted by the message – “An unexpected error has occurred. Check System Event Log for more information…”

If you are encountered similar situation aforementioned before, it is time to ask the help of a 3rd party format tool for USB flash drive.

Reliable flash drive format tool: AOMEI Partition Assistant

Among a great number of format tools for USB flash drive, AOMEI Partition is highly recommended. It allows you to format flash drive to NTFS, FAT32, exFAT, Ext2, Ext3 or Ext4 and enables you to format partition larger than 32GB to FAT32. With simple and intuitive graphic user interface, it is easy to use even for green hand in computer. With small capacity of installation package, it can be installed very quickly. Especially designed for Windows operating system, it can work with 10/8.1/8/7, XP and Vista.

Format flash drive in Windows within three steps

To format USB flash drive with AOMEI Partition Assistant, you should connect the USB flash drive to a working computer running Windows and free download AOMEI Partition Assistant Standard; then do as the following step-by-step tutorial.

Step 1.Install and run Open AOMEI Partition Assistant. Locate your USB flash drive, right click the partition or one partition on it and choose “Format Partition”.


Step 2. In the small pop-up window, set the file system of your flash drive partition and click“OK”.

Format Flash Drive for Mac and PC

PS.: In this window, it is allowed to change cluster size or specify partition label.

Step 3. Return to the main interface. Confirm your operation and click“Apply”>“Proceed” to perform it.



  • If your flash drive present as “Unallocated”, right click the unallocated space and choose “Create Partition” to format it with certain file system.

  • AOMEI Partition is not only suitable for flash drive, but also for SD card, external hard drive and internal hard drive.

Wrap things up

It is not a tough task to format flash drive in Windows 7/8/10. In many cases, you can use Disk Management to format partition on flash drive successfully. Or you can turn to this comprehensive flash drive formatter – AOMEI Partition Assistant to complete formatting operation. Actually, AOMEI Partition Assistant is more than a format tool. It is featured with many other functions. For instance, it allows you to make conversion between NTFS and FAT32; it can help you to securely erase flash drive without reinstalling. Well, you can upgrade it to Professional version if you want to experience more functions like “migrating OS from to GPT SSD”, quick partition and so on.