Command-line (cmd) command to lock a windows machine

Question

Is there a way to lock a Windows XP machine via the command line? The shutdown command doesn't have an option for it.

Answer 1

rundll32.exe user32.dll,LockWorkStation

I've been warned that this isn't recommended (except by Microsoft). The warnings are also centered around the command's close relative, ExitWindowsEx (Which shuts down the computer). I've never had any issues with it, but YMMV.

Schlump: The poodle-monkey may be right. The legend warns that the code is powerful and dangerous.
Nudar: My God. We'd better use it only three or four times. Six, max.
Nibbler: But even a single use could shatter the universe!
Nudar: Got it. Two or three times.

(Source)

Answer 2

On Windows Server 2012 press: Win + L

Answer 3

Since it's not recommended to run LockWorkStation via rundll32.exe, another solution is to use Wizmo. Just run:

wizmo lock

Answer 4

You can also do this from a local machine to lock a remote workstation by using a UNC path:

\\computername\c$\Windows\System32\rundll32.exe user32.dll,LockWorkStation

Getting access denied with Windows 7 workstations, but works with Windows XP.

Answer 5

Note that in Windows Vista/7, you can use the command tsdiscon to disconnect a Remote Desktop session/lock your workstation.

If you use the rundll32.exe user32.dll, LockWorkStation command in a Remote Desktop session (in Windows 7/Vista), the session will continue, but you will just see the lock screen in the Remote Desktop window.

Answer 6

If you have access to Visual Studio's C++ compiler here's the (extremely complicated) source:

//
//LockWorkStation.cpp
//
//Locks the console.
//
//To compile (VC++ 2003, on one line):
//
//      cl.exe /W4 LockWorkStation.cpp /link /RELEASE /OPT:REF /OPT:NOWIN98
//                  /ENTRY:mainStartup /SUBSYSTEM:CONSOLE kernel32.lib
//

#if !defined(_WIN32_WINNT) || (_WIN32_WINNT < 0x0500)
    #undef _WIN32_WINNT
    #define _WIN32_WINNT 0x0500 
#endif
#include <windows.h> 

void mainStartup(void)
{
    LockWorkStation(); 
    ExitProcess(0);
}