Why the USB drive letter is not displayed

When inserting a USB flash drive or MP3, it is always impossible to display the drive letter of the USB stick, what is the problem? In summary, the following solutions are obtained:

1, open the Control Panel, point management tools, Computer Management, Disk Management, you will find a and your USB stick in the same size of the partition, and the display is in good condition, you add in that point, and then add what you want to do, and then you will see.

2, with other U disk or mobile hard drive connected to see recognized, if not recognized, it may be your machine's USB port fault, so you can only replace your machine's U disk interface.

3, if another U disk is recognized, you can take your u disk for a USB test, before and after each mouth to try, should be and your USB port voltage output, and sometimes change the interface will be their own good, and even can be taken out of the extension cable to try the touch of the U disk. My machine now has this phenomenon, the front two mouth only one reader, the other is not recognized.

4. Recall what your machine has done recently and what software has been installed, it is possible that these new updates and software with your USB stick conflict, including anti-virus software upgrades and System package upgrades are possible, reverse operation or in safe mode to see the recognition.

5. Take the USB stick to another computer and try it to see if it can be identified.

6, as you described above, you should be able to "my Computer" "Hardware Device" "Universal Serial Bus Controller" to find the device, update its driver.