By Cherry / Last Updated May 15, 2020

Why cant I copy larger files over 4GB to my USB flash drive?

You have a large enough USB flash drive that enough to store your files and it still has a large free space on the drive. But when you try to transfer some files to the USB flash drive, you will find that only when you copy the smaller files to the USB flash drive, it will be OK, but when you want to copy a large file that is 4GB or larger to the drive, you will get an error like “there is not enough free space on the drive”. As there is still a large space of your USB drive that can hold totally 8GB or more, you may ask “Why can’t I copy larger files over 4GB to my USB flash drive?”

USB flash drive is formatted with FAT32 file system

When you cannot transfer your larger files to your USB drive, please check the information: is the file larger than 4GB? Is your USB flash drive formatted with FAT32 file system?

FAT32 file system was designed in the days of Windows 95. This file system designed with a limitation on the size of the files--The FAT32 does not support the single file larger than 4GB, which means you can transfer files to a FAT32 USB flash drive that as large as the capacity of the drive, but the individual file should not exceed 4GB.

People didn’t anticipate that one day there are such large files. Fortunately, with the development of technology, people designed NTFS file system to counter file larger than 4GB.

Format FAT32 USB flash drive to NTFS file system

To solve the problem that cannot move individual 4GB file to USB flash drive, the most effective way is to change the FAT32 file system to NTFS file system. How to do that? There are many methods.

Method 1. Using Windows tool

If there is no important data on your USB flash drive, you can directly use the Windows to format it.

Step1. Connect USB flash drive to your computer and make sure it can be detected by your Windows. Right click it, select Format.


Step2. Then, choose the format options in the pop out window. Select the NTFS in the File System drop-down menu. ClickStart.


Step3.the Windows will warn you that after formatting, the data on the USB will be erased totally. If there is no important data, you can clickOK to continue.


So there is the question: what if the data on the USB drive is important? It will make a big damage once it lost. Fortunately, there is another way that you can format FAT32 to NTFS without losing data.

Method 2. Using AOMEI Partition Assistant

AOMEI Partition Assistant is a good free disk manger that can mange both your internal hard drive and external hard drive. It has a feature that can safely covert FAT32 to NTFS and vise versa. Thus, even there are important files on your USB flash drive, you can change the file system without losing data.

Step1. Download AOMEI Partition Assistant Standard, install and launch it. You will see the removable disk shown as FAT32. To convert it to NTFS safely, here you need right click the USB drive and select Convert to NTFSunder the Advanced tab.

Convert to NTFS

Step2. It will pop out a window that you can confirm the operation. Click OK to continue.


Step3. You will back to the original window, but you can see the file system of your FAT32 USB flash drive has changed into NTFS. ClickApplyto execute it.

Click Apply

After converting, the data existed on the FAT32 USB drive still exist on the NTFS USB flash drive. The data on the drive would be safe. Besides, you can use the NTFS to FAT32 Converter (Ntfs2Fat32), a wizard that specially designed to convert file system from NTFS to FAT32 without loss of data and vice versa. When the file system changed into NTFS, you can transfer larger files to your USB flash drive flexibly. AOMEI Partition Assistant is more powerful beyond this. You can use it torecover partition, make bootable media, migrate OS to SSD, etc. If you want more features, you can upgrade to AOMEI Partition Assistant Professional edition to get it.