How can upgrade my desktop?

I bought a gaming desktop from bestbuy and it was not what I expected. What and how can I upgrade my desktop so it has a higher FPS

Actually Gaming computer does not expected to be and if you want to play any specific game or a fan of a game, goto that game official site and once check GPU's and CPU's supported by that game. They provide the details of GPU's which supported by that specific game.

Now a days multi GPU support is available, go for that and check whether games supported by these multi GPU's and want to upgrade? if you want to upgrade what type of upgrade you want? whether ram or processor..etc.

If you want better gpu's and cpu's go for AMD and ATI, beacuse I used them for about 4 years and it suported most games and which the performance is also like a dual core processor (actually it is a single core) where I enjoyed alot on my PC.

Higher FPS, which means GPU plays the main role here and choose from the theme of games like adventure, action, racing, strategy..etc and so I can help you deciding the gaming PC with good configuration.