For persistent locks, advanced measures are required. The user can open an and use the mountvol command with the drive’s volume GUID to dismount the volume without a drive letter. Alternatively, the diskpart utility allows the user to select the disk and use the offline disk command, which forcibly resets the lock state. A final nuclear option involves disabling the “Automount” feature in Windows via mountvol /N and rebooting, preventing Windows from automatically claiming newly attached drives before Transmac can access them.
At its core, the “locked drive” error is a manifestation of Windows’ volume locking mechanism. When an operating system accesses a storage device, it typically requests exclusive lock privileges to prevent data corruption. A locked volume cannot be written to or dismounted by a second program. Transmac, which requires direct, raw access to a drive’s sectors to modify HFS/APFS structures, requests this exclusive lock before performing any operation. The error appears when Windows denies this request, meaning another process—often invisible to the user—holds the key. drive has been locked by another program transmac
Resolving the error requires a methodical, escalation-based approach. The first and simplest step is to . The user should ensure File Explorer is not browsing the target drive. Disconnecting and reconnecting the drive often releases stale locks. If the error persists, the user should open Disk Management ( diskmgmt.msc ) and verify the drive is “Online” but not “Active” in a way that suggests system use. A powerful intermediate step involves using Microsoft’s Sysinternals Process Explorer or the built-in Resource Monitor (go to the CPU tab and expand “Associated Handles”) to search for the drive’s volume name or device path, revealing which exact process holds the lock. For persistent locks, advanced measures are required
The primary culprit is almost always the Windows operating system itself or a background application erroneously claiming the drive. Common offenders include (if the drive has a drive letter and has been accidentally clicked), antivirus real-time scanners (which may scan a newly connected HFS drive for threats), disk management services (like diskmgmt.msc running in the background), or automatic Windows Backup and Indexing Services . In some cases, the drive’s own firmware or a previous improper ejection of the drive from a Mac can leave a “dirty” state, causing Windows to lock the drive preemptively. A locked volume cannot be written to or