GEForce fx5200 video card help?

I have a sony vaio and went to best buy and they told me what card to buy. It's PCI normal, not express. I installed the video card, hooked up monitor, turned on pc, and it won't load, it keeps recycling on splash screen and starts over. I put old card in and tried to install driver for new card and it says new driver is not compatible with current video card. no crap, but without the driver, i can't run the new card, but new card won't load without driver. Am i making sense or what am i doing wrong. I installed an ati card no problem on my other pc and thats agp. no problem, whats wrong with this one please.