You can try to find the application that is currently using the disk device in Task Manager, follow the steps below:
- Press the "Ctrl + Alt + Del" keys to open the Task Manager.
- Access the Task Manager, in the Process tab, locate the applications that are using your disk device.
- Right-click on the selected application and choose "End Task".
Note: Be careful selecting and ending processes, If you are not sure what process it's causing the problem, just skip this solution and try the next.
Try to eject the drive in Disk Management, follow the steps below:
- Right-click on "This PC" and click Manage.
- Under Storage, click Disk Management.
- Locate and right-click the USB device you want to remove and click Eject.
Note: If it's an external hard drive that you're going to disconnect in the Disk Management, you will get an option "Offline". The next time you put the drive back to the computer for use, you need to go back to the Disk Management and turn it to "Online" state.
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