Welcome to the first real Windows post :) Now, I know this place mostly has a Linux bias but really, The Node is about solving technological problems…it’s just that Linux makes it easier to do so. As my main interest and inspiration for starting this site was Linux, it has a Linux slant…but I use all sorts of computers. Since July I have become responsible for a Windows network as well as my yummy Linux servers. While I don’t hold Windows very highly, I have been using it…even at home with my new gaming laptop (I tweeted about the joys of Crysis 2 on max detail last week).
So there are bound to be little problems that crop up. This particular problem is so seemingly prevalent on Windows that I just took it as Windows being dreadful. This is when you have an external USB hard drive that you plug into Windows and Windows makes the “bing bong” noise…yet no drive pops up in Windows explorer. Your brow furrows, and you probably do what I did which was to switch it off and on again (grin). Still no luck. However, this isn’t Windows having shoddy USB drivers or anything like that. It’s totally fixable and here’s how.

Note: This fix can also be achieved with Windows XP, but the location of various options and windows may have been moved. Anyway, there are two main ways to fix this. The first way is more common, less complicated in cause and solution.

As you probably know, Windows uses drive letters to distinguish between partitions. I think this is a bone-headed method of file system design, but fine. Anyway, in order for your USB drive to show up as…well…a drive, Windows has to assign it a letter when the USB subsystem alerts it to a new device being connected. No drive letter, no drive to use.

Before we start, make sure that you’ve disconnected or switched off any other external USB devices you may have attached to your computer else it’ll make identification of the problem device difficult.

So, first make sure your USB drive is plugged in and switched on. You’ll hear the “bing bong” sound Windows makes when it’s alerting you to a new USB device being attached. As expected, the drive doesn’t show up.
Open the Start menu and right-click on “My Computer”. From there, left-click on “Manage”. This requires Administrator privileges. From the left panel on the new window, click on: –

System Tools -> Device Manager

From the tree list, expand the “Universal Serial Bus Controllers” option. You’ll probably see many devices, but you only need to look for one, the “USB Mass Storage” entry. If you see more than one, you didn’t take my advice above and switch off and disconnect any other USB hard drives you have. Go ahead and do that and then come back :)

If you only have the one entry for “USB Mass Storage”, that’s your drive. Right-click on it and choose “uninstall” from the options. Switch off or disconnect your drive and then power it up again. This will allow Windows to attempt to re-install the driver for the device. If that was your problem, you should now see your device assigned with a correct drive letter. Done.

If this didn’t work, you’ll need to try the second method.

From the Start menu, select:-

Administration Tools -> Computer Management -> Disk Management

In the bottom middle panel of this new window, you will see a graphical representation of your disk drives. “Disk 0” is usually your drive C: and should not be touched. If you have more internal drives or partitions, they will also show here. In order to match up your external USB device to the devices listed, either match it up by the approximate size listed or simply switch off and on your USB drive to see which entry vanishes and reappears. Once you’ve identified your device, right-click on the blue bar running along the top of the device entry and select “Change drive letters and paths”. Click change and choose an unassigned drive letter. Save your changes and reset the device and it should show up! If it was not seen there, go to “Action” on the menu bar, click on “Rescan Disks” and it should appear.

The blue bar menu is all greyed out and I cannot select the change drive letter option!

If you get this, you have a GPT Protective partition which means that the drive was probably installed on a Linux, Mac or Windows XP 64-bit edition machine. You can override this and get a functional drive, but you cannot save the data as the following solution is a data destructive process. In my case, I didn’t mind, but if you do, consider using the parent operating system of the drive to read the data.

In any case, you won’t be able to recover the data under Windows 7. The drive is inaccessible and Disk Management reports that the drive has a GPT Protective Partition on it. The drive cannot be re-partitioned and formatted in this state, so you’ll need to clean the drive before you can use it.
First, make a note of the disk number listed in the Disk Management window as you’ll need this information in a minute.

Open a Windows command prompt window and enter:-


From the diskpart prompt, type: –

list disks

You’ll get back something like: –

Disk ### Status Size Free Dyn Gpt
-------- ------------- ------- ------- --- ---
Disk 0 Online 698 GB 0 B
Disk 1 Online 111 GB 0 B
Disk 2 Online 298 GB 1024 KB

Select the disk number for your device that you noted down earlier with: –

select disk [NUMBER]

Where [NUMBER] is the number you wrote down. Windows will say that “disk [NUMBER] is now selected”. Now enter: –


This removes the disk’s partition and signature from the drive. After you are returned to the diskpart prompt, type “exit” and go back to your Disk Management window. Windows should now be aware that the drive is uninitialised and should prompt for the wizard. From here you can reinitialise and format the drive. If you’re using a regular USB drive, you’ll probably want to format it as FAT32 (or exFAT) so that it can be used on older versions of Windows, Mac or Linux. Be aware – this format will take ages. Once it’s done, close the Disk Management window and power cycle your USB device. It should now should up with the assigned drive letter :-)

27 comments so far

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  1. Thank you! This was really helpful today.
    Total Comment by Josh: 1

  2. Thanks! Win 7 did not reconize my USB disk (Ultimate Komplete 8). First I tryed the first step to deactivate. But the solution was the second step to change drive letter – (in fact there was no drive letter) Now it works.

    Thanks to Josh sharing his problem an Jon comming up with the solution
    Total Comment by Olav Andreas Randen: 1

  3. Here is the problem that I have that does not have a solution so far:
    My Motorola Razr M when connected via USB shows up in the the device manager as a USB Composite Device but NOT shows up under Disk Drives AT ALL. Uninstalling the USB Composite Device driver and reinstalling it back does not change anything. My phone does show up in Windows Explorer under “Computer” but NOT as a drive and cannot be mapped to any Drive letter (NO option to do that). I tried to find a way to access it in DOS Command prompt but to no avail. Any ides ?..
    Total Comment by JakeM: 1

  4. Thanks for the tip. Win 7 lost a USB drive E. Now it is back.
    Total Comment by TangoEV: 1

  5. Nice one! Lived with this problem for a while. Google found this page and problem now solved. Cheers Jon!
    Total Comment by Davy Jones: 1

  6. i cant clean the disk it says error bla bla i cant clean it
    Total Comment by jewel: 1

  7. same problem??
    Total Comment by Yve: 1

  8. Thank you very much! Super helpful!
    Total Comment by bhibphunki: 1

  9. THANK YOU! This saved my night. Much appreciated.
    Total Comment by iamjackshandle: 1

  10. THANK YOU!!!!!!!! This post helped me a lot :))
    Total Comment by JoJo: 1

  11. Thanks. worked for me in windows XP. Solved my problem.
    Total Comment by Joris: 1

  12. Problem not solved :( After selecting the disk with DISKPART and doing the clean command, I receive this error (translated):
    An error in DiskPart: The system can not find the specified file. Please consult the event log system for more information.

    The USB drive is recognized by device manager and works correctly on other computers.
    Total Comment by Sven: 1

  13. I was trying to avoid buying a new drive and couldn’t find this solution anywhere!!! You really saved me a lot of time and money. Thank you.
    Total Comment by Ian: 1

  14. Worked like a chum
    Total Comment by Lennon: 1

  15. For those who got “Access Denied” on diskpart, or some other problems:

    I just found a program on another forum named mbrfix. It runs on win 7 32 and 64 bit, and using the drive number I got from diskpart, I was able to fix my USB with these steps…

    1. I used diskpart to find the drive number (in my case, 1)
    2. I ran mbrfix64 /drive 1 driveinfo
    This verified that that is the drive I wanted to modify
    3. I ran mbrfix64 /drive 1 clean
    This removed all partition info. If you had any data it will be lost at this step
    4. From disk management I can now add a partition and reformat my drive

    To get mbrfix, google “mbrfix” and the first result should be a site called sysint dot no. Thats the one!

    Thanks for this article, and I hope this addendum helps others!
    Total Comment by David: 1

  16. Did this on Windows 8, Massive help!

    Had to go the diskpart route – a few things (maybe specific to Win8):

    1) Disk Management can be found under “Control Panel->System and Security->Administrative Tools->Computer Management->Disk Management”
    2) exit Disk Manager before cleaning the device or else you will get an I/O error
    3) it’s LIST DISK, not LIST DISKS

    Total Comment by Eric: 1

  17. Thanks for this. Was very helpful.
    Total Comment by L1f2z3: 1

  18. Hi

    Thanks for heading in the good direction. ( same pb with windows 7)
    A Further step was to enter: “autmount enable” while in diskpart.

    No more need to add drive letter :)
    Total Comment by edgd: 1

  19. Thank u……bro
    Total Comment by SANTHOSH: 1

  20. Win 7 64Bit Dell Inspiron 620MT System
    I had a WD 1TB Elements External USB 2.0 Hard Drive on this system for almost 2 years without ever having any problems. I changed it for a Wd 2TB USB 2.0 Drive which installed fine (Plug & Play) I formatted it NTFS and it worked fine using the same backup software as used on the old external drive and I thought “Great” six days later my daily backup failed. I found that the HDD had disconnected from the PC and I thought strange, the only way I could get it back was unplug the IUSB cable and plug it in again and hey presto it all worked again for another four days then it happened again, and it keeps happening totally at random.
    The WD Elements External Drive is Mains Powered and USB 2.0 connected and there is nothing at all wrong with the drive, I have tested it to destruction using WD test software, DOS and Dells own Test Software so I know it’s not the drive. The PC is fully up to date on drivers and chipsets, bios, win updates etc.

    I am totally stumped and can only think its windows, I have now tried everything I could find on the net in terns of a resolution but without any luck, I do see hundreds of others with the same problem.

    If anyone can help contact me it will be appreciated
    Total Comments by Mike Griffin: 2

  21. when I followed Jon procedure to reinitialise and format my USB disk after the old partition was cleaned, Disk Manager in Win 7 used MBR as the default partition format as my USB disk is less than 2T. In that format menu, it seems that for >2T disk, a GPT format (GUID partition format) is recommended.
    Total Comment by SCHAN: 1

  22. Hi Schan

    I will give the GPT format a try and see what happens, I still have the same issue but have further narrowed it down to this;

    Monday to Saturday inclusive at 0130am My system using Macrium Reflect Pro auto backs up my “C” partition size 109.92Gb.

    On Sunday it backs up at 0130am the “c” partition of 109.92Gb then at 0430am it backs up the whole internal hard drive comprising 3 partitions, these are
    1. Dell Utility (2GB) 16bit FAT Partition.
    2. Recovery NTFS (Active)19.69Gb
    3. “C” OS NTFS Primary 109.92Gb

    This is when the connection to the 2TB USB Drive Fails (Corrupted), The USB Drive is still there on My Computer but I cannot write to it.
    If I simply unplug the USB and just Plug it back in again the problem clears and I can then write to the drive using the same Macrium Reflect Program that I always use for all the above.

    That is what I find weird, it works fine Monday through Saturday but fails on the final (2nd backup operation) on Sunday.

    Hopefully GPT Format will fix it.

    Total Comments by Mike Griffin: 2

  23. yeah , it’s working………….great :)
    Total Comment by naveen: 1

  24. DiskPart clean option is G8, Actually it’s create the MBR again and resolve the issue like it was never happened. :)
    Total Comment by Md Qamrul Hoda: 1

  25. thanks friend …..
    i have do this since “on clicking the blue bar menu ->selecting the change drive letter option . but this option was not coming so i do the following …
    a) right clik on blue bar -> clik on delete volume.you will see the bar colure become black. now again click on “black bar” .then click on “new simple volume”.
    after this you will see the new window “new simple volume wizard”.
    now start clicking next->next and …
    finally you will get you pen drive is asking for open folder….enjoy…
    Total Comment by Shailesh Agrahari: 1

  26. Awesome, worked well. thanks
    Total Comment by shiva: 1

  27. ive tried to do disk management option and i go into the disk management and it says loading disk configuration information while the hard-drive is plugged in. the second i pull said hard drive out it loads and shows the actual computer harddrive and thats all.
    and ive also tried the uninstall but it just continually keeps loading but never completing. would appreciate any and all help
    Total Comment by nathan Cuthbert: 1

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