Guys, thanks for these suggestions, but I don't see anything on the broken LCD panel. IT is gone with 20 odd cracks.
So, I cannot go to the display setup or anything. I don't see the right click.
Whatever I need to do has to be done at boot time because that is the only time the external monitor comes on.
The previous two posts do answer your question. windows is defaulting to the internal display. if your laptop came with a quick switch display option that would be your best bet just hit fn and the key associated with flipping the display from internal to external. or use the windows shortcut provided above.
the reason you see the monitor come on during boot is simple. all monitors plugged into a system during the boot process on most system will show the boot screen until windows takes over and shuts down all monitors but the ones currently configured.