Nowadays files are saved both in the hard drive and on USB memory devices. This brings the problem of sometimes deleting or losing files from both places. This is the reason a tool like My Flash Recovery exists, which can recover files that have been deleted, lost or corrupted, but exclusively on USB memory devices.
My Flash Recovery works with USB devices in FAT 16 and FAT 32 systems. It does an exhaustive search for all the lost information. You can preview all the files found and choose which ones you want to restore.
My Flash Recovery can even recover files from USB devices that have been low level formatted.