And, you will get not enough memory error when you attempt to transfer a file larger than 4GB to the USB drive. So, no matter how many GBs of free space you have on your USB drive, it won’t allow you to save the new file. The prime cause for this USB says not enough space issue is by default your USB flash drive is preformatted with the FAT32 file system, wherein the maximum limit of a single file is 4GB.
Even though there is plenty of free space available on the USB drive you will be not allowed to save new data onto it. And, if you look at the USB, you will see empty space. Sometimes, when you try to move/copy new files (larger in size) onto USB flash drive, the error message appears like “ there is not enough space on removable disk.