How do I go from dual monitor back to the single monitor s..

Archived from groups: comp.sys.laptops (More info?)

I have a Dell Inspiron 9300 with an ATI Mobility Radeon X300 with
128MB. Before I started using a dual monitor setup, I was able to
display my desktop or a program I was running on the built in display,
on an external display, or on both by using the "Fn F8" control on the
keyboard.

I changed to a dual monitor display and extended my desktop onto the
second monitor. I now have a need to go back to the original
configuration and, specifically, need to be able to display a running
program on the built in display AND on the external monitor (in other
words, i need both to show the same thing). I have unchecked the
"Extend Desktop" option and I can toggle between the internal display
and the external display by using "Fn F8". However, when I activate
both displays, I can only see the desktop on the primary display.

What am I missing?