How to use DOS!

[Kimonio]

I mean the lights on the keyboard, or on laptops, that tell you if your battery is dying or if CapsLock is on.

[Sethster]

That will take more than coding, that would require tinkering with the actual computer to install lights. Doing something like that would be a lot harder. You're not going to be able to get that to work without messing with your keyboard.