Windows 10 Problem Ejecting USB Mass Storage Device: Safely Removing a Drive That Says It Is In Use
You finish copying files, select the “Safely Remove Hardware” icon, and choose your USB drive. Instead of the reassuring “Safe to Remove” message, Windows says “Problem Ejecting USB Mass Storage slot88 Device. This device is currently in use.” When the Windows 10 problem ejecting USB mass storage device message appears, it is tempting to just pull the drive out.
That message means some program or process still has a file or folder on the drive open. It might be a document you forgot to close, a File Explorer window, an antivirus scan, a thumbnail preview, or a backup or sync tool watching the drive.
Removing the drive while a file is in use can corrupt that file, or in bad cases damage the drive’s file system.
Finding the program holding the drive lets you eject it cleanly.
What Usually Triggers It
The drive stays busy for these reasons:
- A document, photo, or video from the drive is still open.
- A File Explorer window is showing the drive’s contents.
- Antivirus, indexing, or a backup tool is scanning the drive.
- Windows is still writing cached data to the drive.
The Explorer preview pane can quietly keep a file locked even after you close the document.
First Steps to Try
Close what might be using the drive.
- Save and close any files opened from the USB drive.
- Close every File Explorer window, then try ejecting again.
- Wait a minute in case a scan or copy is finishing.
- Open Task Manager and close programs that may have used the drive.
- Right-click the drive in This PC and choose Eject.
If the message persists, find the exact program.
If the Problem Continues
Identify the locking process.
- Press Windows + R, type resmon, and press Enter to open Resource Monitor.
- Open the CPU tab and expand Associated Handles.
- Type the drive letter, such as E:, in the search box.
- Note the program listed, then close it normally or end it in Task Manager.
- Eject the drive again.
For a stubborn case, sign out of Windows or shut down the PC, then remove the drive while the PC is off.
For drives you unplug often, open Device Manager, find the drive under Disk drives, and open Properties > Policies. “Quick removal” disables write caching, so Windows finishes writing immediately and pulling the drive out is less risky.
Protect Your Data First
Never pull the drive out while it is being written to. If you must remove it, shut down the PC first. Keep copies of important files in more than one place.
The Bottom Line
The eject error means a program still has the drive open. Close files and Explorer windows, use Resource Monitor to find the culprit, or shut down before removing the drive.