lcd laptop to lcd projector

[Black]

hi there,i have an acer laptop that i don't know much the model.the problem is one day i want to present one of my assignment.first at post the projector lcd show same the display at the laptop lcd.when i log on to the window the projector is blank is like the cabel is not connected,but i was check all the cabel is connected,why this could happen?

[PrntRhd]

It has to sync up with the projector, usually fixed with a reboot.