Help with Midi Device Input

I'll take a swing at this. You used to see your soundcard and integrated audio interfaces as midi input devices? I've never seen that before. Normally the GM softsynths found on audio interfaces are for midi to audio output only. If you connected an external device like a Midi interface THAT would show up as a Midi Input Device. The error messages you got refer to audio only and are what you get when the audio device can't handle the project's audio settings. If your project settings are higher than your soundcard's capabilities it will be disabled and its Midi sounds won't be available.

Your best course of action, in my opinion, is to buy an external audio interface that can handle higher sample rates as well as the ASIO driver mode. Then you can forget about using your internal soundcard's GM midi module and use the soft synths in Cakewalk. You can probably do that with your Creative Labs card already though you may have higher latency than you are comfortable with. Whatever you do I recommend disabling your integrated sound device found on your motherboard. That is your weakest link and you don't need it.