Quick Question about Specs

[Highonlife]

As you can see by the bottom you can see my specs and they aren't the greatest ever but I didn't buy this computer to game I bought it to surf the web. I bought this computer in 2010 so it is obviously outdated. I wanted to know if I get a bigger graphics card will I be able to run games faster? Right now I only have a Raedon 4250 which if I'm correct that isn't really the greatest compared to like Raedon 6000+. So is my processor just to small and do I not have enough RAM? I am not really a computer expert but I know more than the average person. I was also wondering if 3 gb of ram is enough I really want to do an LP of Super Mario Sunshine. So in a nutshell I was wondering if just getting a new video card could make it possible to play or do I need to add RAM and proscessing speed. Please no mean comments! Should I just forget about it or is there hope like could I just add a new hardware.