Q: Non recognized USB external port by windows 7 64 bit.__

I have a generic (Medion)  US B flash drive that windows 7 64 bit read when I first used it. After the first time, it doesn't recognize the external port when I plug it in.  Did I do something wrong after the first time using it?  How do I get windows 7 to recognize when I have it plugged in?  I plug it in my USB port  which works with other things, but when I look on MY COMPUTER, nothing shows up.  What can I do to get it to work?




Have you tried the thumbdrive in another computer to be sure it is still viable?


Try a System Restore back to before the drive disappeared.

How to Do a System Restore in Windows 7


If needed :

References to Vista also apply to Windows 7.

Do these to clear corruption and repair/replace damaged/missing system files.

Start - type in Search box -  COMMAND   find at top of list -  RIGHT CLICK  -  RUN AS ADMIN

sfc /scannow

How to Repair Windows 7 System Files with System File Checker

Then run checkdisk (chkdsk).

How to Run Disk Check in Windows 7


Then lets refresh the USB Stack

Control Panel - Device Manager - click anywhere in the blank/white area - then VIEW -
Show Hidden Devices

Now look everywhere EXCEPT USB Controllers for your device and if you find them (may have more than one of each) under Disk Drives you may have several - RIGHT CLICK and UNINSTALL for all instances. (There may be none.)

Control Panel - Device Manager - USB Serial Controllers - RIGHT CLICK on EVERYTHING and UNINSTALL all except the category itself - REBOOT - this refreshes the drive and the USB stack

This KB shows the XP how to and the Vista and Windows 7 methods are identical

Here is a utility to help but do the above 1st.

USBDeview is a small utility that lists all USB devices that currently connected to your computer, as well as all USB devices that you previously used. Run it Options and check the 1st three choices to see if any are there.

You would remove all instances of the devices then reboot.


If needed try both of these :

Tips for solving problems with USB devices - and a Mr Fixit

Hardware devices not detected or not working - Mr Fixit


This might be helpful to determine if incorrect driver is loading.

DriverView - Free - utility displays the list of all device drivers currently loaded on your system. For each driver in the list, additional useful information is displayed: load address of the driver, description, version, product name, company that created the driver, and more.

Hope this helps.
Rob Brown - Microsoft MVP <- profile - Windows Experience : Bicycle - Mark Twain said it right.

Rob Brown - Microsoft MVP - Windows and Devices for IT 2010 - current
Windows Insider MVP 2016 - current

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Views: 8,177 Last updated: March 13, 2018 Applies to: