How to fix ERROR_WRONG_DISK (34)

Description

The wrong disk is in the drive. This error occurs during a file transfer when Windows cannot find the expected volume or disk that the source or destination path belongs to. It most commonly appears when copying files from removable media such as USB drives, external hard drives, or optical discs that have been disconnected or swapped mid-operation.

Causes

• Removable drive disconnected mid-transfer — the USB drive, external HDD, or SD card was unplugged while TeraCopy was still reading or writing files.
• Drive letter reassigned — Windows assigned a different drive letter to the disk after a reconnection, so the original path is no longer valid.
• Optical disc swapped — a CD or DVD was ejected and a different disc was inserted before the transfer completed.
• Virtual drive unmounted — an ISO or virtual disk image was unmounted while files were being copied from it.
• Network share disconnected — a mapped network drive went offline or was remapped during the transfer operation.

Solutions

1. Reconnect the drive — plug the removable device back in and retry the transfer. Make sure it is fully recognised by Windows before resuming.
2. Check the drive letter — open File Explorer and confirm the drive is mounted under the same letter TeraCopy is using. If the letter has changed, update the source or destination path in TeraCopy and retry.
3. Keep the device connected — avoid unplugging drives while a transfer is in progress. For large operations, ensure the device has a stable connection before starting.
4. Re-mount the ISO or virtual drive — if copying from a virtual disk image, remount the ISO and restart the transfer.
5. Restore the network connection — for mapped drives, confirm the network share is accessible and the drive is still mapped, then retry.