laptop using external monitor no image on both

Hi I have a acer aspire 9300 with a cracked screen and i use xp OS and a hp monitor as external display, all this being said I installed system mechanic 9 on the laptop I ran the system analize function and then restarted the system and now I have no image on either screen, the laptop powers on but no image or sound, I installed the same program on another laptop and did the same thing and rebooted just fine can anyone help?

 

What happens when you press the cycle display key combination on the laptop?

 

where is that ? :-o
I don't know much about computers, like i said I can't see anything on both screens, but the green lighted button that shows that is powered on. thanks.:-o

 

where is that ?
I don't know much about computers, like i said I can't see anything on both screens, but the green lighted button that shows that is powered on. thanks.

 

It should be along the top row of keys and have little boxes that are supposed to represent the screen. You probably hold Fn and hit that key along the top.