Most stereos have an RCA output that you can connect to the computer's sound card; if not, you can use the stereo's mini-plug headphone jack to send audio to the computer. After connecting the stereo to your PC, you can record its audio output using the GoldWave audio editor. GoldWave is capable of recording CD-quality WAV audio without any additional plug-ins, and a free trial version of the program is available from the developer's website.
1). Connect your stereo to the "Line In" port on the computer's sound card using the RCA-to-mini-plug or mini-plug-to-mini-plug cable.
2). Launch Goldwave. Press the "F11" key to open the "Control Properties" window. Select the "Device" tab.
3). Click the drop-down menu under "Device" in the "Record" section. Select "Line-In" from the menu. Click "OK."
4). Click "New" from the "File" menu. Click the "Sampling Rate" drop-down menu and select "44100." Type the desired length of time for the recording into the "Initial File Length" field, using the format "Hours: Minutes: Seconds." Click "OK" to create a blank waveform of the specified length.
5). Click the "Record" button in the GoldWave "Control" window to begin recording. Press the "Play" button on the stereo. When the recording finishes, click the "Stop" button in GoldWave and press "Stop" on the stereo.
6). Click the "Save" icon. Type a name for the recorded audio into the the "File Name" box and click "Save" to save the recording. Click "Play" to listen to the recording.