Unable to safely uninstall USB flash drive phenomenon

When using a USB flash drive, we often encounter this situation: after the USB interface of the computer is plugged in, follow the normal operation, click "Unplug or Eject hardware" in the lower right corner of the taskbar, then click "Stop USB Mass Storage device-Drive" and the USB Mass Storage device devices are now safely uninstalled from the System dialog box, but there is another dialog box, "You cannot stop the universal volume device now, please stop the device later." After checking, the program files on the USB stick are closed, and there is no data transfer between the computer and the USB stick. So why is this happening?

After repeated research, guess the USB stick inserted in the Windows Task Manager should be added a corresponding process, the hardware normally unplug the corresponding process automatically end, when the process does not end properly when the hardware will not be able to pull out properly. To verify this conjecture, we first open the Task Manager, go to the "process" column, notice that the lower left corner shows: "Number of processes: 23", and then insert a USB flash drive, and then focus on the "number of processes", but when the system found the hardware, everything shows normal, the number of processes is not as I imagined into 24, Instead, keep 23 unchanged. In this case, the USB stick is inserted without the corresponding number of processes, then this phenomenon is not good explanation.

Just as we helplessly click on the tray icon, want to uninstall the USB drive, suddenly found that when the "Stop USB drives" after the number of processes became 24, that is, the unloading of hardware to be a process "responsible", when the hardware uninstall, the process also ended. After many experiments, found that the name of the process is rundll32.exe, haha, the original is the familiar link program.

So, is there a process that is not capable of uninstalling the hardware? I happen to encounter a "can't Stop the device" opportunity to open the Task Manager of the process bar, and then experiment, each end of a seemingly related process, the test to see if you can pull out the hardware. After the end of a few useless processes, found that there are 3 identical rundll32.exe processes exist at the same time, to the end of these processes, we found that the hardware can be deleted normally. Really kung Fu, it seems that the crux of the problem is still on the rundll32.exe. Through this study, we conclude that: the USB stick can not be unloaded normally, the process bar must have no end of the rundll32.exe (of course, some rundll32.exe may be related to the running program in the system), The end of these several rundll32.exe process, the U disk will certainly be able to unload the normal.

Warm tips:

If this can not stop the phenomenon of the device, it is possible to set up a batch file, the input "Taskkill/im rundll32.exe", Save as Delusb.bat, in the event of a failure to run a bit. This method is more convenient.