Multiple Monitor Considerations for Older Programs
Generally, older applications do not need changes to work on multiple monitor systems. For most, the system will appear to have only one display. System metrics reflect the primary display and fullscreen applications show up on the primary. The system handles minimization, maximization, menus, and dialog boxes.
However, some programs will have problems. Some that could have problems are remote control applications, those that have direct hardware access, and those that have patched the GDI or DISPLAY driver. In these cases, the user may be required to disable any monitor beyond the primary monitor.