I recommend Winamp for MP3's and SoundRecorder for WAV's.
Windows Media Player 7.x is a resource hog, it will most likely cause your audio to break up.
To launch SoundRecorder Click on START --- RUN
Type SNDREC32 and click on OK

If you would like for Sound Recorder to handle all your wav sound files.
In Windows Explorer Press & hold the SHIFT button and right click on any wav file.
Then select Open with from the menu.

Scroll down until you see Sndrec32 click on it once to highlight it.
Make sure you have a checkmark in the Always use this program to open this file box.

If you do not see Sndrec32 in the list. Then click on Other and browse to C:\WIndows\Sndrec32