Connecting and then using an external display

I have a Dell Inpiron N5110 laptop and Id like to connect a Viewsonic display to it. I've tried connecting directly to the VGA port and to the HDMI port using a HDMI to VGA converter cable with no success. The display says 'NO SIGNAL' using both the laptops HDMI and VGA ports.

On a previous Dell Inspiron laptop, running XP,  I had no problem connecting and using the Viewsonic. On that laptop all I had to do was right click on the desktop, click Display Setting and Video Output to the VGA port. Win7 doesnt have that option. 

Can someone tell me how to get this external display working off of my 5110 Win7 laptop?