Is the Thumb drive brand new or has been used on another computer, could it have been formatted/reformatted at that use? What size/capacity is it? All the drives I use came factory-formatted as FAT32 up to 64GB, don't have a larger one, yet. Windows has a formatting limit with FAT32 of 32GB, I use Linux Mint to manipulate partitioning of larger drives with FAT32 [have done up to 500GB], Windows can use NTFS and exFAT for larger than 32GB.