This function is specific to OS/2 Version 2.1 or higher.

This function causes an application program to attempt to unlock the system.

#define INCL_WINMESSAGEMGR
#include <os2.h>

HAB     hab;          /*  The application anchor block. */
PSZ     pszPassword;  /*  Password string. */
BOOL    rc;           /*  Return value. */

rc = WinUnlockSystem(hab, pszPassword);