What to Try When Your USB Device is an "Unknown Device"

Here are some common causes and solutions for users facing an "Unknown Device" problem.  This post is a follow-up to Why is my USB device not detected or comes up as "Unknown Device"?.

1) The USB device is "hung".

The USB device may have encountered an internal error and simply stopped functioning.  The device will have a code 43 in Device Manager.  Removing all power from the device (e.g. unplugging and re-plugging the USB cable and also the power cable if it has one) will reset the device and allow it to enumerate successfully.

2) Worn or faulty USB connectors and cables.

Over time USB cables and connectors can fail.  Try plugging it into a different USB port, and also using a different USB cable if it is removable. The device will have a code 43 error in Device Manager.

3) No driver is installed, and the USB device does not report a device description string.

In this case Windows was unable to find a driver for the device, and the device did not report a device description string.  The device will have a code 28 in Device Manager.  To resolve this problem you will need to find a compatible driver for the device, typically by contacting the device’s manufacturer.

4) There is insufficient power to start the device.

If the device is downstream of a bus-powered hub, the device can enumerate successfully but may not be able to start due to insufficient power.  This a bus-powered hub cannot supply more than 100mA to a port, whereas a self-powered hub can supply 500mA.  The device will have a code 28 in Device Manager.  To resolve this problem, plug-in the hub’s power supply (if it has one), move the device to a root hub port, or move the device to another hub that is self-powered.

5) The upstream hub has failed or is "hung". 

If the device is connected to an external hub, try moving the device to a different hub or a root port.  If the device enumerate successfully, try power-cycling the hub or removing/replacing it.  Device will have a code 28 in Device Manager.

6) The USB device has failed.

It is possible that the USB device itself has suffered a hardware failure and is no longer functional.  You will need to replace the device.  Device will have a code 43 in Device Manager.

-Martin Borve

Comments (39)

  1. Invalid Hardware ID: VID_0000&PID_0000 says:

    Invalid Hardware ID: VID_0000&PID_0000

  2. I think that my problem is #6, however, the device is not connected, there are no error codes in Device Mgr. There is no apparent damage to the port, drivers report as up to date, what next? TerryV20.

  3. AnirudhKhandal says:

    I connected my Drive to TV. It still functions correctly on it. But it is not recognized in XP or Windows 7. Any suggestions? Has the file format change. The drive is not getting displayed in the Disk Managemnet also.

  4. Lee Prestridge says:

    Device is unplugged and not in use, still getting the unknown device message.  Tried uninstall, delete, update, etc. and STILL cannot get the error message to go away.  Help.

  5. Rich says:

    My phone has code 43 what do i do? it worked before on W8?

  6. David says:

    My problem began in Windows 8 when I was looking at the startup tab in task manager and found two instances of Util-Desktop enabled.  Upon disabling them, my USB keyboard and wireless USB mouse quite working.  Now the systems states they are not recognized even though I reenabled Util-Desktop, shut down the system, disconnected and reconnected the devices. Device Manager shows Code 43 on Unknown USB Device (Port Reset Failed).  Any ideas?

  7. David says:

    Follow up my previous posting.  The issue is on a laptop where the USB just will quit recognizing the USB devices.  The only way to reinitialize is to power off, remove the battery and let it sit.  Then afterwards reinstalling the battery, applying power and booting up.  

  8. Jan says:

    This computer is only 4 days old.  So I guess you can not help a disabled dummy like me either.  Thanks anyway.

  9. Ron says:

    My WD signature mini external hard drive will work on my old laptop and desktop but not on the new ACER laptop.  I've tried everything above, but none work.  Wha to do?

  10. Duane says:

    Thanks, This got me in the right direction faster.  The 4th port on my powered hub is apparently bad.  I switched to the main ports on the PC and the device worked.  I used a different port on that hub and the device worked.  I tried other devices on the 4th port an none of them work.  So I guess my hub has lost a port, sure seems like a hardware issue now.  Kind of surprised I would lose only one port.

  11. Brandon says:

    See but it's not just 1 USB port for me. It's all of them, one gets power and tried to work. I'm pretty sure the other 2 are just dead though.

  12. How can I just rid my machine of all USB drivers and install anew? says:

    Is there a way to fix the two 43 errors? I'd like to rid my machine so I can have the USB stuff come back anew. I have removed all of the plug in USBs but the two errors are there. I uninstall, but they eventually come back. Windows 8.1 here. No solutions in sight.

  13. rajesh says:

    My WD2500XMS-00 is not idenitified in windows 7 explorer and glitters as unknown device in windows device manager. How to configure and make my WD work in my home PC??

  14. Eliyas Yakub [MSFT] says:

    Dirty connector can also cause the device to not show up:



  15. Peter says:

    My Sony Ultrabook with Win 8 opens the USB montarily to show the content, then it drops off with an error "Windows has stopped this device because it has reported problems".

    Copy of one event

    + System

     – Provider

      [ Name]  Microsoft-Windows-Kernel-PnP

      [ Guid]  {9C205A39-1250-487D-ABD7-E831C6290539}

      EventID 411

      Version 0

      Level 3

      Task 0

      Opcode 0

      Keywords 0x2000000000000000

     – TimeCreated

      [ SystemTime]  2013-11-18T21:48:23.613358100Z

      EventRecordID 654


     – Execution

      [ ProcessID]  4

      [ ThreadID]  14276

      Channel Microsoft-Windows-Kernel-PnP/Configuration

      Computer VAIO

     – Security

      [ UserID]  S-1-5-18

    – EventData

     DeviceInstanceID USBVID_0000&PID_00045&6de9790&0&11

     DriverName usb.inf

     ClassGUID {36FC9E60-C465-11CF-8056-444553540000}




     Problem 0x2b

     Status 0x0

    None of the above are applicable to my case. Can someone help please?

    Thanks Peter

  16. FreakinA says:

    YEa well ive been using my game controller every morning for the last 3-4 months.  I move the laptop to the living room for a day and back and now neither controller works, error 43 plus the port address request failed.

    Its absurd that something as old as usb would still be breakable.  Large enterprises are whats broken in this world.  #stopthemegacorps

  17. linda70@gmail.com says:

    my ipad will not turn on—–says it has to be connected to ITunes——been trying to do that without success—–how can I get this thing into recovery or just the way it was 7 days ago?  How maddening when you pay 500.00 for something and it's locked down like a federal prison.

  18. theoson says:

    Code 43 – "the device is damaged and needs to be replaced"? Malarky! The android device in question works properly tethered to my older Windows 7 computer. Thank you Microsoft. You failed us again.

  19. jj says:

    Thanks, just unplugging and plugging reset it,

  20. ArtGs says:

    What if a USB port suddenly starts working intermittently at best and no error code is visible in Device Manager (Vista 32bit)?

    This started about two months ago, and it's driving me nuts. More specifically: one of my Acer laptop's USB ports suddenly stopped working. The optical mouse doesn't function at all on that port (no 'unknown device', no error message, no error code), while both the portable hard drive and a couple of USB flash drives (all of which work fine on other USB ports) trigger the 'unknown device' message in Device Manager.

    To identify the malfunctioning port, I plugged in a flash drive and got several screenshots of the details. The 'problem code', however, appears as '00000000'.

    I checked the power options, I've used the 'scan for hardware changes' (no error), 'disable'/'enable', and 'uninstall' options, rebooting the system in the latter case to re-install the device, I've rolled back the driver, I've tried starting in safe mode – all to no avail.

    Acer support's only advice was to re-install Windows from scratch. A lame solution, but I tried it anyway: for about 2 days, the port worked properly – after that, it went dead again. This suggests that some update might be the culprit, however, System Restore did not fix the problem and, of course, wiping out the hard drive and freezing all updates is not a solution.

    Any suggestions on how to identify what causes the problem and on how to fix it? Perhaps you can suggest a hardware diagnostic tool that could give me a clue?

    Thanks for any advice.

  21. John B says:

    It appears this problem is being ignored at MS. What IS the latest for this issue (which I have since going to Windows 8.1. Using the info supplied by the MS USB CORE TEAM requires a PHD in Computer Technology. Is close to worthless for the average user. My USB device that's getting a code 43 is somehow permanently installed since I have no external devices connected. I'm using the same monitor as for the past 6 years if that's a USB device. It seems to me that somewhere along the line a device is failing. To know that the device is failing should indicate that the machine knows what device it's looking for and did not find. Why the hell can't the error message tell us "Machine was looking for Device XXXXX and did not find it in the Device Descriptor List, which can be viewed at YYYYYYYY." ? Come on guys ! The data is available somewhere, share it with us.

  22. Saphris says:

    I would say, since they never replied to any comments/questions since 2011, that it's hopeless to find out whats wrong with this code 43. :

  23. MichMerr says:

    theoson: I'm having the same issue (working Android device, unknown device in Windows). I think the damaged device description may be accurate because I get the same result on different machines. The whole device doesn't have to be damaged, just the USB data connection circuit. One bad solder joint or damaged connector…

    Anyway, unless it can be successfully plugged into a non-Windows computer, it's probably a hardware issue and not something that Microsoft can solve for us.

  24. Swan says:

    Device is recognized by other USB ports.  Problem is with driver version 6.1.7601.16328 provided mi rosoft.  It is happening after windows update.

  25. mohammad altaher says:


    this is the solution for your problem if you need any help contact me on youtube

  26. Chris says:

    *** Thank you Microsoft, thank you USB-Stack-Team…. for nothing! >| ***

    Invalid Hardware ID: VID_0000&PID_0000

  27. Mughal prince says:

    also have same problem once left side USB stop working & now all over stoped … tried best to recover even with reinstalling windows but nothing change & don't a single active port

  28. David Gray says:

    If you suspect the connection for the USB device is bad it is possible that the pins connecting the device to the usb hub are dirty.  This was the case for my thumb drive that sat in my pocket for weeks.  A little WD-40 and a soft flat wooden toothpick to clean up the pins fixed my problem.  Do not spray WD-40 directly into your device! I'm sure there is more "technically" correct fix, but this works in a pinch.

  29. Eugene says:

    Thanks a lot, solved my problem with code 43, cleaned the usb connectors then reconnected the device, it seams that the usb device got hung because the connectors were dirty.

  30. Sammi M says:

    As I'm an old lady, I have read this info with the thought of possibly finding out what is happening with my computer. I accidentally printed out page after page of what has been going on with my LG motherboard.  I

    have been trying to find an answer to what this PNP Device ID means.  Thought it might have something

    to do with my "messages on my computer telling me "My session has ended."  and my inability to send

    e-mails out in response to ones coming in.  TWC can't help. Sure wish I had my old  AMD system back.

    So perhaps I may have a USB cable problem.  I've tried everything.  I may start unplugging and replugging

    I may find that it will allow me to do my volunteer work.  Thanks.  I think I must take a "computer

    tech" course…smile.  If you guys are frustrated, just think about how much we old geezers are…Sam

  31. Kevin says:

    Thank you. I've been looking for an hour now and the problem was my USB cable. I could not connect my phone to my computer. Changed the cord and it worked perfectly.

  32. heena sharma says:


    i’m having 2 Tb pen drive and 1 Tb hard disk but both are showing as unallocated in disk management . I already formatted both devices but still showing that “system cannot find the file specified”.i’m using window 7 in my computer. please help me …

  33. Stephen Mann says:

    “The last USB device you connected to this computer has malfunctioned” never stops. HELP!!
    There is no USB device plugged in.
    There is no USB hub.
    No programs are running.
    There are no unknown devices or errors in the Device Manager.
    I have removed all USB device drivers and the O/S reinstalled them.
    All power-off options are unchecked.
    Recent software installations were removed.

    Yet, I keep getting this message every 5 seconds.

    Short of reinstalling Windows and all of my programs, does anyone have another thought?

  34. Jeff Schwager says:

    In my case, it was a driver issue. Uninstalled the USB drivers and then installed latest drivers from the manufacturer’s website. That remedied the problem.

  35. Angry Guy says:

    nothing works for me I tried all this! >:o I hate windows 10!

  36. ali says:

    Device will have a code 43 in Device Manager.

  37. ali says:

    unknown device USB root hub error 43

  38. ali hemmati says:

    You will need to replace the device. Device will have a code 43 in Device Manager.

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