By Emily / Last Updated December 3, 2019

“USB Flash Drive not showing correct available space”

“Several days ago, I transferred a lot of files from my computer to my SanDisk 8GB flash drive. Till yesterday, I deleted all the transferred files from the USB drive, but it was still showing pretty full when I checked it in “storage” and very little available space. I am pretty sure the deleted items have definitely gone. So why the device is still nearly full? What can I do for this issue?”

Why doesn’t USB drive show full capacity in Windows?

Before proceeding to how to format USB to full capacity, it is better to figure out what might cause USB drive not displaying full capacity:

> The USB drive has been made to a bootable disk. If you have used the USB drive to make bootable media before, it might also show the wrong capacity now. That’s because some systems probably change its partition when writing booting data.

> The USB drive comes with an unallocated space. We all know that only allocated space can be used while the unallocated disk space cannot. In this case, you can add the unallocated space to an existing partition.

> The USB drive is larger than 32GB but formatted to be FAT32, which is known to be compatible with 32GB disk at most.

> The USB drive is formatted on different computer frequently. For example, it has been formatted on Mac computer recently, but now reformatted back to Windows FAT32, then its capacity might get shrunk.

> The USB drive gets damaged. When this occurs, the entire disk size in Disk Management might shrink, or the USB drive shows 0 media.

How to format USB to full capacity in Windows 10/8/7?

Now, we will show you how to format USB drive to full size in Windows 10/8/7. Since formatting will delete all data on the USB drive, please backup anything important via AOMEI Backupper before proceeding.

Method 1. Format USB drive to full capacity via Command Prompt

Step 1. Run Command Prompt as Administrator: Click the “Start” button and enter “cmd” in the search box; then right-click “Command Prompt” to select “Run as Administrator”.

Step 2. Type the following commands in the Command Prompt window and hit “Enter” key.

  • diskpart

  • list disk

  • select disk 1 (Caution: please be very careful to select correct disk number before cleaning or formatting operations, or you might wipe wrong disk by mistake.)

  • clean

  • create partition primary

  • format fs=ntfs quick

Diskpart

Now you can open Windows Explorer to check if the USB drive is restored back to full capacity.

Method 2. Restore USB drive to full capacity via AOMEI Partition Assistant

If you feel this first method is difficult to you, you can utilize a free third-party disk formatting tool-AOMEI Partition Assistant Standard. It can format USB storage devices like external hard drive, SD cards, pen drive to NTFS, FAT32, Ext 2, Ext3, Ext4 and exFAT in Windows 10/8/7 as easily as possible. Besides, it is also able to copy partition, resize partition, delete hidden partition on USB drive and more.

To format USB to full capacity:

Step 1. Free download, install and run AOMEI Partition Assistant Standard, right-click the USB drive and select “Format Partition” from the drop-down menu.

Format Fat32 Partition

Step 2. Choose a proper file system according to your USB storage space and the current operating system, and click “OK”. Here we choose “NTFS”.

Choose Ntfs

Step 3. Hit on “Apply” and “Proceed” to commit the pending operation.

Proceed

Final words

Both Command Prompt tool and AOMEI Partition Assistant Standard can help you format USB to full capacity. The latter software is more powerful to manage disk partitions. For example, it can wipe USB drive completely, format 0 bytes USB drive, convert data disk between MBR and GPT without losing data.

If you upgrade to AOMEI Partition Assistant Professional, you can enjoy more amazing functions such as convert booting disk between MBR and GPT styles without data loss, allocating free space from one partition to another, extending NTFS system partition without reboot.

If you are planning to format USB to full capacity in Windows Server 2019/2016/2012/2008/2003, please try AOMEI Partition Assistant Server.