Microsoft DOS lock and unlock command

Quick links

About lock and unlock

About lock and unlock

Lock allows a user to lock a drive, enabling direct disk access for an application.

Unlock allows a users to unlock a drive, disabling direct disk access for an application


The lock command is an internal command that is available in the below Microsoft operating systems.

Windows 95
Windows 98


LOCK [drive:]

drive:Specifies the drive that needs to be locked.

UNLOCK [drive:]

drive:Specifies the drive that needs to be unlocked.


lock c:

Lock the C: drive

When typing the above command you will receive the below prompt.

WARNING: The LOCK command enables direct access by programs that can CORRUPT file names and DESTROY disk data, resulting in the loss of files on your disk.

Are you sure (Y/N)?

unlock c:

Unlock the C: drive

Note: If an errors is indicating that a process cannot continue because the hard drive is locked the unlock command cannot resolve these error messages.

Additional information

  • See our lock definition for further information and related links on this term.