How to save file as wav or wmp

Thank you, Clyde, for trying to help, but I didn't actually understand a word of that! HOW do I "play the .not file through my computer sound card, and then record the output from my sound card"? I wouldn't have the slightest clue as to where to begin. If you can give me a step by step, I'd really appreciate it. I'm not really too worried about the sound quality, as I only use the "Grand Piano" voice (all the others sound too fake, and I only play piano anyway).
Thanks again!