Helping people with computers... one answer at a time.

"Device cannot be stopped" can be a frustrating error if there's no obvious cause. Turning off device power or unplugging anyway isn't really safe.

If I have an external hard drive connected and running (but not being used or accessed through my overt actions) and I get the message "The device ... cannot be stopped right now. Try stopping the device again later.", would be safe to turn off the external drive (assuming it has an on/off switch) and then unplug it from the computer? Or would switching it off be just as risky?

Ultimately turning off the device is pretty much the same as unplugging the USB cable. So, the short answer is no, it's not really a safe alternative.

Unfortunately it does happen sometimes that a USB device appears to be in use and cannot be stopped. I'll walk through some of the approaches you can take to removing the device while minimizing the risk of data loss.

And no, pulling the plug isn't one of them.

The message that you're seeing in Windows XP:

USB Drive Cannot Be Stopped Right Now

(Windows Vista and Windows 7 have similar messages.)

Here are the steps I take whenever I encounter this (which is often):

"Sometimes I don't follow my own advice."
  • I check for Windows Explorer, or Windows Command Prompts that are open and are displaying the contents of the external drive in question, or have that drive set as the "current" drive. This is by far the most common cause on my machine. Simply closing which ever I find, or having it display something else that isn't the removable device instantly resolves the issue.

  • I fire up Process Explorer, as outlined in Why do I get "device ... cannot be stopped right now" trying to safely remove my USB drive?, and use it to see what application might have a file or "handle" open to something on the removable device. Once I identify the application I then take action appropriate to that program - perhaps closing it, perhaps going to it and doing whatever makes sense in that application to stop it using the external drive.

  • I wait a while. Seriously, sometimes the process using the external drive will just disappear on its own.(Yep, this is the "Try stopping the device again later." part of the error message.)

  • I shut down the machine. This is the ultimate. Once the machine has been shut down then by definition it's safe to remove anything you want. (You can use "Restart" as long as you're careful remove the device after Windows has truly shut down, and before it begins to reload - in other words while the BIOS self-test screen is showing.

You'll note that just pulling the plug wasn't on the list. Smile

However...

I'll be honest.

Sometimes I don't follow my own advice. Sometimes if none of the steps short of rebooting have worked, I'll just wait awhile, paying careful attention to disk activity. If the device has truly been idle for "a while" - I'll remove it anyway.

Caution: If you follow my example you may lose all the data on the device. Heck, you may lose the USB device itself. It's a risk I run because I'm impatient and don't want to wait for a reboot. And it usually works.

And I'm also very well backed up. I'd never take that inappropriate shortcut if the data on the USB device was, say, the only copy of the data.

So, weighing all the risks, I sometimes break the rules. (I include it here because there are times when you honestly are in a hurry, or a reboot just isn't in the cards for some reason.)

I don't recommend that you do the same. Take the time to reboot your machine to be safe.

Article C3938 - November 29, 2009 « »

Share this article with your friends:

Share this article on Facebook Tweet this article Email a link to this article
Leo Leo A. Notenboom has been playing with computers since he was required to take a programming class in 1976. An 18 year career as a programmer at Microsoft soon followed. After "retiring" in 2001, Leo started Ask Leo! in 2003 as a place for answers to common computer and technical questions. More about Leo.

Not what you needed?

27 Comments
G L DeLozier
November 29, 2009 3:30 PM

When XP tells me my device cannot be stopped and to try later, I find that if I immediately right click the "safely remove hardware" icon and ask again, it will say it is safe to remove it. I view it as NOW it knows I want to shut it down and prepares it so I can. Wouldn't this be considered the safe procedure?

Munkeh Junk
November 30, 2009 7:22 AM

No, this is not considered the safe procedure.. you should always turn off your your PC before hand.

Ken B
November 30, 2009 9:41 AM

Thanks for the honesty about not always following your own advice on what you "should" do. I have to admit that I, too, have unplugged the USB cable (*not* the power cable) on a device that simply wouldn't allow me to "safely" remove it after failing to find what had it open.

But, I agree that it's a last resort action, short of shutting down the computer itself, and know the possible consequences, and would never recommend doing it

Ziggie
November 30, 2009 10:54 AM

Unlocker works for this situation:

http://ccollomb.free.fr/unlocker/

(I do not work for them nor am I associated, just enjoy their product).

David
December 1, 2009 8:21 AM

Here's what I do: If I have saved nothing to the drive (say, a USB thumb drive) and it was inserted only for reading of files, then I ignore this warning and pull the drive out anyways. (My theory is, I've saved no files to that drive, so I don't care what Windows says.) If on the other hand, I have saved some files to that drive, then I get paranoid and pretty much follow Leo's steps above; the reasoning is that **now** I want to help Windows flush buffers and update everything on that drive, so that all my files newly written to that thumb drive are not corrupted.

Gabe
December 1, 2009 8:22 AM

Leo,

Could you elaborate on this...

With a USB drive plugged in, if I go into Device Manager (right-click My Computer and select properties), expand disk drives, right-click the USB device and select properties, on the policies tab, there's an option to "Optimize for quick removal". Would you trust this as an I-never-need-to-safely-remove-my-device-again type of setting?

Never? Never say never. I'd try to use safely remove if at all possible.
Leo
02-Dec-2009

Rajitha
December 1, 2009 8:24 AM

i have installed this too called 'unlocker' which basically unlocks the files from processes. whenever i get this type of a message, the easiest thing to do is to right click on the usb drive and select 'unlock' from the menu.

Peter Baker
December 1, 2009 8:54 AM

Try right-clicking My Computer and selecting Properties, then switch to the System Restore tab. If System Restore is monitoring the external drive, disable it from this dialogue box. Then restart the PC, verify the external drive isn't being monitored and then see if you can now remove it. It worked for me.

Frank Walker
December 1, 2009 8:54 AM

What about unchecking "enable write caching on the disk"? In My Computer right click the device, click properties, click the "hardware" tab, click properties, click the "policies" tab, make sure "enable write caching on the disk is unchecked.
This is for windows XP.

Alan W
December 1, 2009 9:57 AM

See also perhaps http://safelyremove.com/index.html

ian reece
December 1, 2009 10:28 AM

Above: "Try right-clicking My Computer and selecting Properties, then switch to the System Restore tab. If System Restore is monitoring the external drive, disable it from this dialogue box." Once this is done, the drive is no longer being monitored and one can "Safely remove Hardware". Unfortunately, as far as I know, if System Restore is enabled, there is no way to permanently (ie surviving reboots and unplugging/replugging drives) cancel system monitoring for any non-C drive. So, every time one plugs in a drive, one has to go thru the procedure above in quotes.

Oren Phipps
December 1, 2009 1:37 PM

Instead of turning the computer completely off I have found it sufficient to simply Log Off a much quicker process. remove the drive and then log back on.

Stan Carton
December 1, 2009 1:55 PM

Hello Leo: Thanks for the advise on removing drives. I use a lot of naked drives and have tons of data to keep backed up. I hate it when I get the message about "remove later". I have completely shut down the computer and removed the drive/s. This works great. I have never lost anything. If the data is important and you want to remove the drive shutting down becomes a great alternative for me. Thanks again. Stan

Philipm
December 1, 2009 2:41 PM

I unplug mine by putting my machine in stand by mode. Doing this turns off the MY Book activity light which tells me its off. Much faster than restarting everything.

Standby makes me nervous. I would *hope* that the system flushes disk buffers and the like, but it's also possible that that's not the case. To running applications Standby (and hibernate to some degree) don't appear as if the computer has shut down at all. It's possible that even in standby removing the device could leave unfinished files and unflushed buffer. I have no idea how likely this is, but it makes me nervous.
Leo
02-Dec-2009

1101doc
December 1, 2009 6:20 PM

Another vote for Unlocker. Right click the drive in "My Computer," choose Unlocker, and when it opens, select "Unlock all." 99.5% success for me.

Kikzamchine
December 1, 2009 10:55 PM

This works for me. . .
Open task manager.
Go to the Processes tab.
End Process "explorer.exe".
All windows will definitely close including the task bar.
Select file on task manager.
Select "New task (Run)"
Type, explorer.exe then hit enter or ok.
Task bar will be back. Eject the device again (Safely remove hardware).


Pilu
December 1, 2009 11:01 PM

There is another way, posted on:
http://blogs.msdn.com/pandrew/archive/2007/01/15/unlocker-utility-for-ejecting-usb-drives.aspx

and the little program can be downloade from:

http://download.cnet.com/Unlocker/3000-2248_4-10493998.html

Hope it will some help
with respect
Berta Istvan (Stephen)

RikkU
December 1, 2009 11:51 PM

At times it could also be a case of the original application still locking the device. eg: if you were using a wordprocessor to edit a document directly on the USB drive, even after closing the document (but not the application itself) you may not be allowed to stop the device. If in doubt, close all open applications.

Another situation is where your device is being scanned by your anti-virus program. You can either stop the scan or wait until it finishes.

Hope this helps.
RikkU

josh
December 2, 2009 5:52 AM

unlocker always works for me. if it doesn't, you haven't given it enough time to close every process referencing data on the drive. Ending 'explorer.exe' process is just unnecessary.

in hardware properties also (right click device, properties).. some clicks later.. there should be an option to allow for safe removal anytime but you get no cache/indexing or something like that. good trade-off though.

SystemCrash
December 2, 2009 1:09 PM

Another quick thing I do is to "Unmount" the drive by removing/changing the assigned letter for that drive using the Disk Management Console (diskmgmt.msc). This forces the handles to be removed from the logical drive.

Logan E. Wing, III
December 3, 2009 2:13 PM

Go to My Computer (XP) or Computer (Vista). Right click the drive letter of the drive you want to remove. Left click Eject. Wait for the safe to remove message, then remove. Has worked so far for me.

nick
December 6, 2009 4:25 PM

I have been researching this for SIX months. I have NOt found an ideal solution for this.

1. we need a way to FORCE a dismount of the usb drive. These drives stay locked up just from activity of indexer, explorer, etc, things that may not be WRITING data, but just are LOOKING at the drive.

2. I will try UNLOCKER

3. process explorer is good, BUT there are processes that show up that I have NO CLUE what they are, and am hesitant to shut down those programs without knowing what they do


4. See Truecrypt (disk encryption program). If you start truecrypt, and MOUNT an encrypted drive, and then later try to UNMOUNT it, and something is inadvertently accessing that encrypted drive, truecypt has an option to FORCE dismount. THIS is what is needed for the usb drives.

Leo, KEEP UP the research on this topic, because it affects LOTs of people, and not being ableo to shut these down is a pain

nick

Theo
December 7, 2009 12:52 AM

I can only backup the statement to never remove a USB devicejust like that. I wrecked a stick once doing that.

All my collegues always told me that it is unnecessary to shut down the device, "you can just pull it out, it doesn't hurt". So it did that once. The very next time I plugged the stick into a computer, it seemed fine, but after a some 10 seconds it disappeared from the drive list. No matter what I did, I couldn't get it back.

The only way to see the stick again, was unplug it, wait a little (as if a capacitor had to discharge or so...) and then replug it. Again: it would be visible for a couple of seconds, and then disappear. The longer I waited before replugging it, the longer it would stay visible (hence my suspicion of a capacitor discharging), but never longer than 10 seconds or so. I managed to pull off all important data by copying it onto my hard drive during that few seconds (took me a couple of sessions), but by all practical means the stick has become unusable.

So I disconnect my sticks properly again, no matter what my collegues think of it...

Colin Mac
December 7, 2009 1:41 AM

Many people try to close a USB drive with a double RIGHT click which displays a box and ask you to select the device you wish to close, this doesn't always work!!! A LEFT click will display the message 'Safely Remove Hardware'.... one click on this does the trick!

Adam
December 14, 2009 5:13 PM

Just wanted to say thanks for the information contained in the article and comments.Was trying to isolate a hard drive but still have easy access.
Unlocker among others,has provided that link,and removed possible mistakes.
Thanks

Yeppers
August 11, 2010 7:10 PM

Leo, I have a portable hard drive for which I have no choice but to turn off the computer in order to safely remove the drive. I would like to avoid this lengthy process by selecting the “Optimize for quick removal” policy as described in Gabe’s 12/2/09 comment. However, your reply to his comment seems to imply that there is some risk to using that method (“I’d try to use Safely Remove if at all possible”). What is the risk? Thanks...

Not sure I'd overstate it as a "risk", but ... 1) it may slow down access to the drive as the system has to make sure it's always ready to be removed, and 2) ir may cause data to be written more often to flash drives wearing them out more quickly.
Leo
14-Aug-2010

trythis
March 13, 2012 3:24 PM

control panel/administrative tools/computer mgmt/disk mgmt - select disk to remove and choose ''offline''. you can remove it now by ''safe removal''.

Comments on this entry are closed.

If you have a question, start by using the search box up at the top of the page - there's a very good chance that your question has already been answered on Ask Leo!.

If you don't find your answer, head out to http://askleo.com/ask to ask your question.