Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

My daughter had her thumb drive plugged into my desktop, doing some work. She finished, logged off of her account and I logged into mine. I noticed that she left her thumb drive in the USB port, and so I tried to safely eject it, but I get the following message:

Problem Ejecting USB Mass Storage Device

This device is currently in use. Close any programs or windows that might be using the device, and then try again.

OK, I give up. I just logged into my account and the first thing I did was try to eject her thumb drive. What in heck is currently using it? I don't have anything else opened/running when I got that message. How do I determine what program is apparently running and doing whatever it is, against that USB drive? How do I get whatever it is, to stop so I can safely disconnect the thing?

share|improve this question
up vote 12 down vote accepted

You can use Unlocker to find out what program has it opened (figure 1) then close that program (Unlocker has a portable version). If it is Explorer, you can restart Explorer—an easy way is to hold Ctrl+Shift and right-click a blank area in the Start menu (figure 2). If you cannot exit the program, you can use Unlocker to force the handle closed.

Figure 1: Unlocker showing processes with open handles

enter image description here

Figure 2: Restarting Explorer in Windows 7

enter image description here

share|improve this answer
So how do you get the "exit explorer" context menu? – Moab Feb 8 '12 at 3:05
Oops, sorry. Fixed. (I don’t use that method; the few times I actually had to restart Explorer in Win7, I used an option called “Restart Explorer”. I can’t figure out where it is right now—I’m in XP at the moment—but next time I’m in 7, I’ll see if I can find it and add it as well. And no, it was not a third-party one that used taskkill, it was built-in, to my surprise—ie, Microsoft basically acknowledging the need to restart Explorer.) – Synetech Feb 8 '12 at 3:11
+1 for the "Exit Explorer" option. Much easier than opening Task Manger and finding the process. – Sonic42 Feb 8 '12 at 5:05
After exit of explorer using context menu, how do you get explorer to reload? ctrl+alt+del twice allows you to open task manager to do it, so it seems better to use task manager to exit explorer in the first place. – Moab Feb 8 '12 at 17:49
It doesn’t reload automatically? It should, that’s part of Explorer (and there’s no point in building in an option to kill Explorer without it restarting). Check the task-manager to see if there are other instances. I find that when there is more than one instance of Explorer.exe the auto-restart function gets blocked (or at most opens an actual Explorer window instead of just the desktop). – Synetech Feb 8 '12 at 18:00

Microsoft has its own utility called Devcon.exe.

From the site:

DevCon (Devcon.exe), the Device Console, is a command-line tool that displays detailed information about devices on computers running Windows. You can use DevCon to enable, disable, install, configure, and remove devices.

DevCon runs on Microsoft Windows 2000 and later versions of Windows.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.