Not sure what kind of chipset used on that motherboard.
To run vista with decent speed, you need > 1GB of memory.
You need DDR2 memory. You can buy a single 1GB DDR2 desktop memory ( PC4200 or PC5300 ) to add to your empty DRAM slot on your motherboard. Or you buy two 1GB DDR2 modules. Take out the module you have on your computer, and install the two new modules.
If you add 2GB of memory, you should see much better performance on your computer.
Typically, you can get 2GB of ddr2-667 ( PC5300 ) memory for 20 dollars after rebates.
For the PCIE video card, that typically runs from 40 dollars to hundreds of dollars.
Having that will help your pc a lot too. But it will be relatively expansive.
If you are in US, you can go to a place call www.dealnews.com to check what is good sales going on.
If you want to shop the stores, you can go to Fry's, compusa, microcenter, officemax, office depot, bestbuy.