laptop keyboard not accepting key combinations

I had recently bought an aspire 5516 notebook vista laptop. Everything was fine until I went to go play my games. I had noticed that certain key combination such as a, d, and c did not work, nor' up, left, shift, and z.

Is there anything I can do to get the laptop to accept the key combinations?

I had still tried numerous google searches, however, I could not find any specific methods to allow my keyboard such combinations.

Does this mean there is no way to allow such things through a configuration?
Or does it even mean I would have to replace the keyboard?

I'd really need to know if there is a method to allow the key combinations.

Is it ghosting? I had a keyboard where it wouldn't pick up more than three key presses at once. Try any other combination of over three keys and see if all of them register.