It might turn or repartition the memory card to 32GB and the rest capacity won't show in Windows.
If you are using a card reader which is compatible with 32GB card at most, but your memory card is 64GB.
For instance, you burn a portable operating system on your removable drive, and you may find that the disk loses capacity. The USB drive is made to bootable disk.
USB flash drive / SD card/ pen drive not showing full capacity can happen for several reasons. Why doesn't USB drive show full capacity in Windows? Do you have any idea to restore capacity? Thanks!" The size does not change even though I format the partition. But I can't do anything to unallocated space. There is large free space on the flash disk when I checked it in Disk Management. The flash drive used to have 16GB storages, but it is 2.19MB in Windows Explorer only after it is made as a bootable drive. The problem is that the USB's capacity shrank. I fixed the system problem successfully but a new problem arose in the flash drive. "Lately I made a bootable USB drive on a USB flash drive for crashed laptop. Let's take a close look at a real cause about this issue: That does not necessarily mean you have to buy a new one, as the capacity can be restored in many cases. It's possible that a 64GB flash drive shows as 54MB only. We can store large amount of data on SD card or flash drive so that we can take them to anywhere without difficulty. Likewise hard drive, USB disks come with different size, ranging 215 MB to 1TB. USB storage devices such as external HDD, USB flash drive, pen drive, memory card, etc, play important role in daily lives. Thus we should get a rough idea about this issue at least. It's really annoying to be unable to use all USB drive's storage, but this issue just happens due to various reasons.
How to restore USB flash drive back to full capacity?.