My son's Keyboard acting weird. keys d, 1-4 do nothing. If press letter 'r' 'run opens'. it just does wierd things when pressing keys.

Try another keyboard.

It was his keyboard. We switched and his did the same on mine. I guess I'll go buy me a new one tomorrow, as I am using the one for the playstation and I don't like it, the keys are too small.

Cheap keyboards are often not very well made and eventually some keys may fail to work intermittantly or at all .
If the keyboard is corded, after it has been used a lot it's common for wires to get broken inside the cable, often right where it enters the keyboard, especially if the cord has been yanked on.
If you think your son is likely to treat the keyboard roughly, spend a bit more and get him a wireless one that is more robust.