
You don't necessarily have to, pre-build computers are good as well as long as they have good specifications.
i know nothing about fancy stuff
i dont even know what RAM is
and again whats wrong with 1.3GHz
RAM stands for Random Access Memory, it's basically how well your computer can run certain programs. 4GB ram is alright, not the best out there, though. I used to have a laptop with 4GB RAM and I clearly saw the difference when I got a 6GB RAM desktop computer.