|Most if not all flash drives originally use FAT32 software partitioning / formatting, not NTFS. That has nothing to do with your problem.|
If the flash drive is plugged into a USB port it can actually work with properly, you probably damaged data on the drive yourself by NOT using Safely Remove Hardware to STOP accessing it when you unplugged it while Windows was running. In most cases you can use certain programs to repair the data damage and have access to your data again.
Troubleshooting USB device problems including for flash drives, external drives, memory cards.
See Response 1: