I have a couple of questions. For 500-600, it is very difficult to make a build with windows and a monitor to do what you want it to do. Your build above is in your price range, but neglects the OS and a monitor, so does that mean we can leave it out? Also you have a monitor resolution listed, but you listed that you are buying a monitor, so do you have one or do you need one? Regardless, I will post two builds. The first will have windows and a monitor included, the second will not, and will have better components.
The monitor can be left out, I will probably just buy one from a local store. I like the second build. Is it much better than the one I posted and will games with high setting work good on it? Thank you!
zared619's builds are pretty good but he forgot that Battlefield 3 is one of the games that just needs a quad core or above to run well in multiplayer.What i mean to say is although the Core i3 processors are usually a very good choice for a gamer their multithreaded performance just isnt good enough for Battlefield 3.With that in mind i can build you a even better PC with a similar price tag.And, ill try to include a hard drive as well.
Nothing against the build posted above, its a good build. More or less though the only game the 965 is better at is BF3. The OP said he is probably playing MMO's. I used BF3 as an example because it is the most bottleneck on the system I posted.