What can I do to my Dell Inspiron 3521 to have PC Games Run better?

My Specs are;
-Windows 8 64-bit
-Intel i3-3227U CPU
-6GB RAM
-Intel Graphics HD 4000 1.5GB

To put it into perspective, I can run Minecraft on the Highest Graphic Settings around 25fps and the Lower End at 60fps. Also I can run Skyrim on the defaulted Low setting and have lag ONLY in extremely hectic situations.

Help?

Added (1). What NVidia or ATI would be suitable for my Laptop? As in, I wouldn't have to also replace my power supply.

Added (2). It is a Dell Inspiron 3521 (15) That's about as specific as I can get, I bought it at Wal-Mart and it was the only one with Intel i3 AND 6GB Ram.

Dylan K

Everything is great Just use an High end "NVidia" or "ATI" Graphics Card. They are best for Gaming (They are made for this purpose). Intel Graphics doesn't play much games.

As you are an laptop user, Go for External Graphics card easy to install and everything just remember to buy at least of memory 2-4GB.

RERIE