I think that pc is still useful for what you're doing, if you make some upgrades. Your motherboard supports phenom 2 quad cores and you can get those used on ebay. You also need to get raise the ram to 4gb as you said earlier. Lastly, ssd drives will give you a dramatic increase in performance...
What make and model of pc is this? Also, do you know what motherboard it's using? If you don't know, download, install and run cpuz from the net. Click on the mainboard tab.