How to Copy Locked Files in Windows

Some files in Windows are constantly held open by the operating system or running applications - the Windows registry, Outlook data files, database files, and virtual machine disks are common examples. Standard copy tools fail on these with errors like "The process cannot access the file because it is being used by another process."

TeraCopy can copy locked files using the Volume Shadow Copy Service (VSS), a Windows feature that takes a point-in-time snapshot of the file system so files can be read even while they are in use.

Enable volume shadow copy in TeraCopy

1. Open TeraCopy and go to the Options tab.
2. Under Transfer options, check Use volume shadow copy service.
3. Click Save as default so the setting applies to all future transfers.

With VSS enabled, TeraCopy creates a shadow copy of the volume before reading locked files. The copy sees a consistent snapshot of the file, avoiding access errors and partial reads.

Run TeraCopy as Administrator

VSS requires elevated privileges. Right-click the TeraCopy shortcut and select Run as administrator. Without administrator rights, the shadow copy request will be denied and TeraCopy will fall back to a direct read, which may still fail on locked files.

Frequently asked questions

Does VSS work on all drives?

VSS works on NTFS volumes. It is not supported on FAT32, exFAT, or network drives. If the source drive uses one of those file systems, TeraCopy will copy locked files without VSS and may encounter access errors.

Will VSS capture the latest version of the file?

VSS creates a snapshot at the moment the copy starts, so you get a consistent point-in-time copy of the file. Any changes made by the application after the snapshot begins will not be included - which is generally what you want for a reliable backup.

Does TeraCopy need to restart to create a shadow copy?

No. The shadow copy is created on the fly when TeraCopy starts a transfer with VSS enabled. The original volume and any running applications are not affected.

What if TeraCopy still fails to copy a locked file?

Make sure TeraCopy is running as administrator. If it still fails, the file may be on an unsupported file system, or another process may be holding a lock that VSS cannot bypass (rare, but possible with kernel-level drivers). As a workaround, close the application using the file before copying, or reboot into Windows PE to copy without any locks active.