Help with my laptop.

So, my computer is pretty crappy. So I need some help determining if I could buy a graphics card and add it or if I need a new computer altogether. Which, may be the case. I just hope it isn't. I already determined the graphics card I'd want. One that's not too pricey. But not too cheap, either. Probably an AMD one. Possibly Sapphire. Forgot the exact number. But, here are my specs.
Processor: Intel(R) Pentium(R) CPU N3520 @2.16GHz
Ram: 4.00 GB (I need to add more than that, I already know this. It's a crappy amount.)
System type: 64-bit Operating System. Windows 8
Graphics: Intel(R) HD Graphics. (It's displayed under display adapters. So, I'm confused if it could be changed out. Or if I'd be able to add another. Or if it's just not upgradeable at all.)
I don't know what else to put here, really. But if anyone could help me determine whether the computer is just complete shit. Or whether I can upgrade it a bit. That'd be nice. Thanks!