A Dell Inspiron 8600 has two options for outputting video to another device: normal VGA out and s-video. Connecting a monitor to the VGA out sends a duplicate of the desktop on the LCD to the ...

If you want a duplicated screensaver, you must also set your desktop to duplicate on both monitors. If you want one screensaver to extend across both monitors, you must set up your displays to extend.

I have two monitors and just about every morning I'll wake up my computer and find that my second monitor "forgot" its "Extend these displays" setting. It's in the setting dialog, it IS still set ...