Broken screen...can\'t use...what screen can I plug in to work


yes I have an external monitor....I tryed to attach but can't get it to work...Is there something I need to switch on the computer?
Thanks for any help
 


Thanks for reply....didn't know about monitor settings...will try that..
I have another monitor...
Thanks for info....have a good day.
 


Yes and I plugged it in and won't let it connect......do I have to do something to my computer to make the switch???

Thanks for reply