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With Windows XP and Windows Vista, I try to remove an external USB hard drive, but usually get the message ""Windows can't stop your 'Generic volume' device because a program is still using it.". I tried closing all programs on the desktop, but it still won't give the "safe to remove" message.

I am generally able to make flash drives safe to remove without a problem.

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1  
Sleep the box, remove the drive once the box is asleep. –  Daniel R Hicks Apr 11 at 11:44

11 Answers 11

up vote 17 down vote accepted

Look for RemoveDrive on this page (direct link to the Drive Tools page RemoveDrive tool section).
Those pages also have good related information.

The RemoveDrive tool is useful also when
you Do not get ‘Safely remove’ option in Tray for USB storage devices.

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Anything that can tell you what is holding the drive is good. I've gotten this after I closed everything, all explorer windows even. So sometimes Windows just doesn't want to let the drive go. –  Joshua Nurczyk Sep 6 '09 at 18:21
    
@Joshua, I have felt that sometimes Windows is Indexing the drive and holds it for that... The "-i" option on RemoveDrive disables the indexing service for a moment to remove the drive. –  nik Sep 6 '09 at 18:22
    
I like Unlocker which is dedicated to the task of displaying and freeing open file/directory handles. –  opello Sep 6 '09 at 18:24
    
This worked for me. Thanks! –  Mike Sep 6 '09 at 18:48
    
Re unlocker: Note that this is dangerous. You will be able to remove your pen drive but you risk corrupting future files when a file handle gets recycled and both the new and the old program try to write data to it. –  Hennes Aug 15 at 21:39

This is due to the fact that there is at least a process/program that is still accessing your USB drive. It may not be enough if you just close all the programs on dekstop, if you are copying folders from/to the USB hard disk, you will get this message.

Try and find what process is holding the resource and either complete or close the process and you should be able to remove the USB hard disk without any problems.

Do let us know how it goes.

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I think this is because Windows itself is still finalising the writes to the hard drive. I get the same message if I try to disconnect straight after copying some files. If I wait until the drive has stopped spinning then it disconnects without any problem.

I haven't been able to find any information on why this is, so if someone could enlighten us I'd appreciate it.

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This is by no means a good answer, but you can always shut down the computer and remove the USB device.

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Actually you can't! You'll hear the drive click. But if it's ejected the click doesn't happen. I don't know if that matters, but I've had problems with two external hard-drives (drive appeared unformatted), I suspect it was because of such shutdowns... –  Alex Oct 9 '13 at 2:24
    
@Alex If you shut a computer down, it can't be using a drive if it doesn't have any power. –  starbeamrainbowlabs Nov 2 at 14:49

There are several reasons to USB being undismountable:

  1. It's in use. Please note that if you're looking at the disk in Explorer, then it's in use!
  2. Windows is finishing copying a big file to or from the disk (rarely the reason)
  3. A bug in Windows causes conime.exe to get stuck on the disk (it may safely be killed)
  4. If the USB drive is formatted as NTFS, the journal of all file updates may still be open
  5. If disk indexing is on for the drive, Windows may be furiously indexing all files on it

My advice is to:

  1. Make sure the USB drive is not defined as indexed.
  2. Wait, and then try again. It might work a few seconds later on.
  3. Buy Zentimo ($29.90) that does a good job of trying to remove the disk. Even if it fails, it still tells you which programs are using what files (I paid).
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Often this will be because the drive is being indexed; right click the drive>properties, and uncheck index. Or the AV is monitoring the drive - turn off AV to test this.

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I found the free USB Disk Eject to be very useful:

A program that allows you to quickly remove drives in Windows. It can eject USB disks, Firewire disks and memory cards. It is a quick, flexible, portable alternative to using Windows’ “Safely Remove Hardware” dialog.

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Nice. I updated the link to refer to the generic product page, which has a far more recent version. –  Arjan May 19 '12 at 9:55

If it's none of the pedestrian/common options, it could be you have the drive listed as 'shared' on a network and have accessed it via another computer. In my case, even though the remote computer was off, it still had a lock on the directories. Unshare and it should work if that's the case.

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Take a look for programs installed recently, which can prevent safe HDD disconnection.

In my case it was Magical Defrag 2: any newly connected disk with new letter assigned was automatically marked, so now after unmark I can safely remove the USB drive.

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  • Right click on the properties of the USB drive in Windows Explorer.
  • In the popup window click on "Hardware".
  • Identify the drive and left click on it once to highlight it, then click the properties box.
  • Click on the Policies tab and select "Optimize for quick removal" and click OK.

If you're sure that none of your own processes are still in use on this USB just pull it out.

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I've noticed this a lot. What we do is to share and then unshare the drive. It's had a 99% success rate. I have no clue why it works, but time to time it says another user is accessing the drive... even though I just shared it only to unshare it. Try that. You'd be surprised at the success rate.

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