Whenever I play a game my keyboard stop working..?

It is correctly plugged in....In the game folder there is this npkcusb.sys driver....When I checked the device manager when my keyboard stoped working....The usb human interface device said that C:\Programs Files\MapleSea\npkcusb.sys is not digitally signed in..I think thats why my keyboard stopped working...Please help if you have any solutions..:)