Steps to installing a new pci gfx card over integrated gfx?

Running on a Dimension 2400, only getting around 15fps with integrated graphics in my game of choice, so I figured I'd upgrade, no agp slot so I went for a half-way-decent pci card...only problem is installing it.

 

 

1.) Physically installed the card (PCI G-Force 5200fx)

2.) Installed the latest drivers for it from Nvidia.com

3.) ???

 

 

I need to know what to do next, it says its working and everything but when I plug my monitor into it I get nothing...I have to plug it into the onboard, intel integrated port still...Do I disable the onboard VGA somehow or..? All help appreciated, if you can do it in step form (so my simple mind can understand) that would be awesome =D