using with external monitor

The desktop died, so I'm trying to use this with my external display for the next couple of days until the parts come in. Long story short I need it to appear only on the external monitor. What do I have to do in the displays menu to get it to send off through the VGA. It will do a dual display no problem, but Whenever I try and set it as the primary monitor, it just blanks out and reverts back to being just the laptop monitor

 

Mine is not death but I would also like to set a bigger monitor as the primary monitor and I get the same problem.

Pierre

 

I've used my 19" Acer monitor only as a secondary monitor and it worked on 1440x900.
I could just drag the browser or a video to the other monitor and expand it afterwards. I think it's better because your mouse goes from one monitor to the other. You can open one or two on the 8.9" and more in the other one.
That's my opinion.