This is the standard way sound files are stored by Windows. Sound samples recorded on the Sound Recorder are WAV files. To find all the WAV files on your PC, go to view menu in the 'My Computer' window and select Details, so you can see what types of file you are viewing. Sound files are listed as file type Wave Sound.
This file format was developed jointly by Microsoft and IBM as the standard format for sound on PCs. WAV sound files end with a .wav extension and can be played by nearly all Windows applications that support sound.
This is the file extension for Waveform Audio, a standard audio format for Windows operating systems, often used for storing high-quality, uncompressed sound. Due to their uncompressed nature, .wav files take up many times more disk space than MP3.