This function enables or disables queuing of physical input (keyboard or mouse).

#define INCL_WININPUT /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HWND    hwndDesktop;  /*  Desktop-window handle. */
BOOL    fEnable;      /*  New state for the queuing of physical input. */
BOOL    rc;           /*  Previous state for the queuing of physical input. */

rc = WinEnablePhysInput(hwndDesktop, fEnable);