Just a update for you guys. I bought a second RAM exactly as mine to enable the Dual Channel feature and now my PC is more decent. It got way better than before.
It was my ram. It was underclocked. My RAM's clock is 1600. It was running as 1115mhz. Now I just need another kit to do a dual channel then it's GG.
Thank you all for the answers.
Let me ask something... The RAM can interfere in any way in the overall performance of the computer? Because my RAM is 1086, not a 1333 like I thought...