Locking and logging off a Windows system can be accomplished through the Command Prompt (cmd) using specific commands. This functionality is useful for securing your system when stepping away from your computer or for logging off users in multi-user environments. Below, I’ll explain how to lock and log off a system in cmd, along with examples and expected outputs.

1. Locking the System

To lock your Windows system using the Command Prompt, you can use the rundll32 command.

Basic Syntax:

rundll32.exe user32.dll,LockWorkStation

Example:

To lock the system, enter:

C:\> rundll32.exe user32.dll,LockWorkStation

Output:

C:\> rundll32.exe user32.dll,LockWorkStation

(No output is produced, but the screen will lock.)

Output Explanation:

• This command locks the workstation, prompting the user to enter their password to unlock it. There will be no command-line output, but the system will transition to the lock screen.

2. Logging Off the System

To log off the current user session, you can use the logoff command.

Basic Syntax:

logoff

Example:

To log off the current user, enter:

C:\> logoff

Output:

C:\> logoff

(No output is produced, but the user will be logged off.)

Output Explanation:

• This command logs off the current user from the system. Like the lock command, there will be no command-line output, but the user session will end, and the user will be taken to the login screen.

3. Logging Off a Specific User (Advanced)

In environments with multiple users, you can log off a specific user using the logoff command with the user’s session ID.

Basic Syntax:

logoff [session_id]

Example:

First, you can find the session ID by using the query user command.

C:\> query user

Expected Output:

C:\> query user
 USERNAME              SESSIONNAME        ID  STATE   IDLE TIME  LOGON TIME
>YourUsername         console             1   Active      none    10/29/2024 10:00 AM
 User2                console             2   Active      none    10/29/2024 10:05 AM

• Suppose you want to log off User2 (Session ID 2). You can enter:

C:\> logoff 2

Output:

C:\> logoff 2

(No output is produced, but the specified user will be logged off.)

Output Explanation:

• This command logs off the specified user session by session ID, allowing administrators to manage user sessions effectively.

Summary

Locking and logging off a Windows system via the Command Prompt can be easily achieved using the rundll32 and logoff commands. Locking the system secures it temporarily, requiring a password to unlock, while logging off ends the user session and takes the user back to the login screen. These commands are especially useful in multi-user environments or when you need to secure your workstation quickly.