►The USB partition file system becomes RAW and cannot be recognized by Windows OS. ►Connecting several USB flash drives to the computer at one time or connecting via a bad USB cable. ►There are some files which are set as hidden due to some unknown reasons. ►A sudden or unexpected power failure occurs when the disk is writing data. ►The USB drive is infected by some virus, or the MBR gets damaged greatly. ►Any partition on this hard drive gets corrupted. ►Remove the USB flash drive in an improper way or during the process of transferring data. In order to fix such issues, we should first figure out why that happens. Many customers may encounter this problem, and it will make things much worse if users have stored a large number of private or important files onto the drive.

That drives me crazy! What can I do to solve it? Thanks in advance. And i found the USB thumb drive flash drive shows 0 bytes in used, free and capacity space. Yesterday I connected my USB flash drive to the computer and tried to open it in the Windows Explorer, and it failed every time along with a message which says ‘ You need to format it before use it’, but I cannot format it since all important files are inside.

Usb shows up as 2 drives