Start Vista Sound Recorder. It can be found in the "Start" menu under the "Accessories" folder. If your computer is running standard Vista, Sound Recorder will record in the WMA format. If you want to force Sound Recorder to record in the higher-quality WAV format, you can start Sound Recorder by typing "soundrecorder /file outputfile.wav" into the "Start Search" box at the bottom of the "Start" menu.
Make sure your microphone is working. Plug your microphone into your microphone jack and begin speaking. If Sound Recorder is picking up sound from your mic, a green sound indicator bar in the Sound Recorder window will begin moving in time with your voice. Alternately, your computer may have a built-in microphone, which you can test by simply speaking toward your computer. Finally, a set of headphones will also work as a microphone if plugged into the microphone jack of your computer rather than the headphone jack. Just speak into the earbuds and look for the green sound indicator bar in the Sound Recorder window.
Press the "Start Recording" button in Sound Recorder to begin recording. Unlike earlier versions, the Vista version of Sound Recorder can record for many hours. When you are finished, press "Stop Recording." A dialog box will open, asking you to name and save your recorded sound file. Choose a name you will remember and make note of the location of your sound file.
Download audio file conversion software. Microsoft recommends downloading an audio file conversion program such as "FreeRIP MP3" (see link under Resources). You will have to install the audio file conversion software, so be sure it comes from a source you trust.
Open your recorded sound file in the audio file conversion software you just installed, and choose the "convert to MP3" option. The audio file conversion software will convert your Sound Recorder file from WMA or WAV format to MP3. If you chose WMA format in Step 1, above, your MP3 will be of low-sound quality and small file size. If you chose to record in WAV format in Step 1, your MP3 can be of a higher quality.