Video card supported?

I recently am upgrading my pc. I'm paying someone to upgrade some of the hardware in a new machine I got. He told me my current pc only supports a PCI only video card. No PCI-Express or PCI-E setup. When I did a dixdiag look up on my display features and my card I get the following

Card name: Intel(R) 82915G/GV/910GL Express Chipset Family
Controller DAC type: Internal
Device Key: Enum\PCI\VEN_8086&DEV_2582&SUBSYS_2A08103C&REV_04


With it being a Intel Express Chipset does this mean that the actual PC can handle a PCI-Express as well? I'm a not really good at knowing this stuff but if I can get something better then a 256MB PCI such as PCI-Express 512MB I would rather do that now then later on down the road find out I can do so and have to spend out more money. Any advice would be much appreciated!