1. Software problem
2. Hardware problem
Based on experience, USB device not recognized largely caused by a hardware malfunction.
The characteristics of the damage
1. When the flash is inserted, show error message "USB device not Recognized"
2. The error message "The last USB device you connected to this computer malfuntioned, and Windows does not Recognize it. Recommendation; Try reconnecting the device. If Windows still does not Recognize it, your device may not be working properly".
The solution to this problem is that you have to repair the damage to the hardware on a USB flash drive. Follow the instructions in the video, how to do it.
1. Open the casing flash
2. Re-hot the tin solder on the flash drive connectors (re-hot four feet connectors)
3. Reinsert the flash drive to be sure, flash disk is back to normal