Add drive scan function that can detect a corupt or bad sector in memory from flash drive or external hdd

Scanning for corrupt or bad sectors on flash memory is illogical and pointless. First of all flash memory chips already have error detection and correction built in, using a variety of techniques to avoid you ever seeing any defects on the device. It is possible that the device could have so many problems that the built-in error correction logic cannot compensate anymore. Bottom-line: at the first notice of any read/write or CRC errors, BUY A NEW DEVICE...!