I am making a game that often requires keys to be held down or pressed simultaneously. I have discovered that if I hold down too many keys, some of them do not register and the motherboard(?) starts making clicking sounds, like I'm overloading something.

It seems that each key has a different value, and if the sum of the key values held down exceeds a certain threshold, the problem arises. I have mitigated this by choosing keys that tend to only contribute small amounts to the threshold, but am still running out of breathing space.

Can someone explain this problem to me, and any possible solutions? I have experienced this before, and it seems to even vary between keyboards. Can software solve the problem? Perhaps some improved drivers?

(I'm just using GetAsyncKeyState.)