I hope this is the good place to write this.
I got an M-Audio Fast Track device.
Exactly this one.

And i have a USB Keyboard.
Casio LK-270
This one.

The MIDI on the keyboard sound way much better in my opinion than the Microsoft GW on guitar pro.

What i want is be able to use the MIDI sound from keyboard, (because it's sound better and i can alternate every tuning easier and fast) while playing guitar trought my M-Audio sound card.

I'll like to be able to play with Guitar Rig or Peavey Revalver in same time then keyboard.

Possible? Probably...

Thanks a lot!

Well, first, MIDI is not sound, but data. If you really like the sound from the keyboard, you'll have to run a cord from the line out of the keyboard to your interface. No reason you can't use Guitar Rig or Revalver at the same time.
Quote by lockwolf
You need one of these for Midi: http://www.amazon.com/Cable-Converter-Music-Keyboard-Window/dp/B0017H4EBG/ref=sr_1_1?ie=UTF8&qid=1303670096&sr=8-1

Like mentioned, Midi isn't sound, its data. There are hundreds of synths, instruments and midi instruments that sound way better than whatevers on your keyboard for free or cheap on the internet.

Ooohh ok!
I like my keyboard because it's fast to change tuning between song...
I've saw the cable you've told me on amazon... !

In what am i supposed to plug this?...

Output from keyboard to?...
I just got two line outputs with the M-Audio card (left and right).

I have a few cable that i can plug in my computer, Output from K-Board to Line in from comp but with the sound card im unable to hear it...

I guess it's very easy to fix... (Well i hope... )! But i don't know how...

Thanks a lot again!

Midi out into a USB port on your computer...
Derpy Derp Derp Herp Derp