If you are encountering this error, here is a review of the solutions ranked by effectiveness:
This happens because Windows is protective of its drives. Even if you don’t have a folder open, background processes are often "touching" the USB stick, preventing TransMac from gaining the exclusive access it needs to format the drive.
This error appears when you try to perform an operation (like restoring a DMG, formatting a drive, or writing an image) and Transmac informs you that it cannot access the drive because some other software on your Windows PC has an exclusive lock on it.
The "TransMac drive has been locked by another program" error is a common frustration for Windows users trying to format, write, or access Apple-formatted drives. This error occurs because the Windows operating system or a third-party application is actively accessing the drive in the background, preventing TransMac from gaining exclusive control. Transmac Drive Has Been Locked By Another Program
Temporarily disable in Windows Security.
Check the system tray for any backup or sync software (e.g., Dropbox, Google Drive) that might be trying to "index" the new drive. Troubleshooting Checklist Potential Issue Recommended Action Write Protection
: Type list disk . Look for the disk number that matches your USB size (e.g., Disk 1 or Disk 2). If you are encountering this error, here is
: Check if your USB drive has a physical write-protect switch.
Learn about standard troubleshooting steps for various error symptoms in the official TransMac Help guide
Windows restricts low-level disk modifications to standard users. Close TransMac completely. The "TransMac drive has been locked by another
: Hardware switches on some USB drives or software-level read-only attributes can trigger a "locked" status. Step-by-Step Solutions 1. Run as Administrator
Security suites may lock USB drives upon insertion to scan them.
Open (or your third-party antivirus like Avast, Norton, or McAfee). Go to Virus & threat protection settings . Turn off Real-time protection temporarily.