Alienware m15 r3 keyboard problem

I have an problem with my recently bought alienware m15 r3.

I think my arrow keys and wasd are kind of synchronized. For example: when i press all arrow keys and w, the other letters (a,s and d) will also get pressed even though i dont press them. this also happens when i press all arrow keys and a, s or d. its the same the opposite way: when i press w,a,s,d and an arrow key, all the other arrow keys also get pressed even though i dont press them.

here are some examples:
- w, a, up arrowkey, right arrowkey = d gets also pressed and left arrowkey gets also pressed
-a, s, d, right arrow key = left arrow key and down arrow key get also pressed
- but if i press for example w, a and right arrow key, nothing aditional gets pressed.
that means that it only gets synchronized if i press an arrow key and letter from w a s d in the same direction (up, right, down or left) and another key.

i looked at the seetings and i cant find anything to deactivate this synchronazation. i use arrow keys and wasd for most of the games i play so please help me with this problem.