I am doing a clean install of Windows 8.1 on an old PC. It was purchased as download from Microsoft Store and written to and booted from a USB flash drive.

It went through all of these steps:

  1. Copying Windows Files
  2. Getting files ready for installation
  3. Installing features
  4. Installing updates

Then at "Getting finished" I am stuck at this stupid dialog box.

Please unplug the following external drive and click OK to restart your computer and finish installing Windows.


How do I tell what physical drive this is? Can I drop to command prompt during installation? And is it safe to unplug it while powered on?

There is no external hard drive connected, none that I can see. There is no USB or FireWire drive connected externally. I think it sees one of the internal drives as external... in some weird way?!

  • Press Shift+F10 to bring up a command prompt, type the following command, and post here the output: wmic logicaldisk get caption,filesystem,size,volumename – and31415 May 28 '14 at 9:28
  • @and31415 Thanks! It's getting devices ready now. The problem was the USB flash drive that I used to boot and install the system from. The main problem was figuring out which one is the F drive. You can post your comment as an answer, I can update it with the output from the wmic command. – Samir May 28 '14 at 9:39


  1. Press Shift+F10 to bring up a command prompt.
  2. Type the following command:

    wmic logicaldisk get caption,filesystem,size,volumename

Example output

Caption  FileSystem  Size          VolumeName       
C:       NTFS        366997504     System Reserved  
D:       NTFS        20974428160   System           
E:       FAT32       80004153344   80 GB            
F:       FAT32       7721713664    ESD-USB          
G:       NTFS        53884649472   Datadisk N
H:       NTFS        315183595520  Backup           
I:       NTFS        59073925120   Datadisk         
J:       NTFS        130668294144                   
X:       NTFS        533640192     Boot             

Further reading

  • 1
    It was that "ESD-USB" device that was the problem. That's the bootable USB flash drive I created to install Windows. I just removed it and was then able to reboot and complete the installation. The Shift+F10 shortcut was the solution. I knew about the wmic command, I actually learned about that a few days ago when I needed it. But I had forgotten about the shortcut to drop to command prompt. Thanks again! – Samir May 28 '14 at 9:55
  • @sammyg You're welcome. The output leaves me wondering what are those K: and L: letters associated with. – and31415 May 28 '14 at 9:57
  • Answering myself: those letters should be associated with empty optical disk drives (ODDs). – and31415 Jul 26 '14 at 13:30

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