lets say I have a computer running Win 7 and the res is 1920x1080. Now i shut down the computer then replace the monitor with one whose max res is 1024x768. What would happen? would the computer default to that resolution or try to output 1920x1080 and present you with a blank screen of somesort?
It would not display, your monitor would probably say no signal detected or it would just be blank.
Just tested this on my external monitor with the Intel graphics utility, it just didn't display, it says no signal detected until the setting reverts back after 20 seconds.