Screen 2 (external) selected as only display, but Screen 2 is not working, so I can't see what I'm doing reselect Screen 1.

[erynnwilcox]

I tried to connect an external display (BENQ projector) to my Laptop (Toshiba Satellite L305, Windows Vista), but the projector will not display the picture. I would also like to solve this problem, but the more pressing issue is this:
Before I hooked up the projector, in the Windows Mobility Center, I selected the option for Screen 2 to be my ONLY screen when hooked up. But since the projector (Screen 2) doesn't display anything, it means I just have NOTHING on either screen when I plug it in. And as far as I can tell, I can only instruct my computer to put the display back on my main screen WHILE the projector is plugged in. But, you see, I can't do that, because I have no display at all. I feel like I'm going in circles, but I just want to make sure I am making sense!
The question is this: How do I command my computer to use both monitors to display my screen while looking at a monitor with no display?

 

[erynnwilcox]

Okay, I fixed the problem myself by blindly fiddling with the Fn+F5 keys until I guessed the right combination. But now I would like to know if there's a way to get my darn projector to work. The VGA to VGA cable works just fine with my husband's laptop (also a Toshiba Satellite), but I get no response from mine.