Something's up with my keyboard

Occasionally, when I go to play this one game (maplestory), when it goes to the login screen, I try to type in my password, and my keyboard doesn't respond. So I exit the program, and check my hardware options on control panel, it says that I don't have a keyboard plugged in. The only way I've been able to fix this problem so far is by doing a system restore. I'm really getting tired of doing this nearly every time I play it, so does anyone know of a better way to fix this problem? Thanks!

 

Well, maplestory is the only online game I play, so I'm not sure if the problem occurs on other games. As for OS, do you mean like Vista? Because that's the computer I have.