Dual VGA monitors on Dell XPS 8500 with NVIDIA GeForce GT 640?

I just purchased a new Dell XPS 8500 and I'm trying to connect 2 VGA monitors to it.
The video card is a NVIDIA GeForce GT 640 1GB GDDR5, which supports dual monitors. It only has one DVi port, so I got an adapter and connected one monitor to that. It also has an HDMI port and a display port but I'm not sure how to connect my other VGA monitor to that?! I tried plugging the second monitor into the standard VGA port on the machine, but it doesn't recognize it and brings the machine to a halt basically.
Trying to avoid buying a new monitor.
Thanks!

Can I just get the DisplayPort to VGA Adapter through Dell for $34 or is there a better option somewhere else?

Thanks!