Visit the Audacity website and download the software at http://audacity.sourceforge.net/. This popular program is feature-packed and versatile. Best of all, Audacity is open-source software and is thus provided for free.
Double-click the Audacity file you downloaded. A pop-up installation window will appear. Follow the onscreen instructions until installation is complete.
Connect your tape player to your computer. A standard audio cable is necessary for this. The type of cable depends on the audio outputs of your tape player and audio inputs for your computer. A cable with mini jacks on both ends will likely suffice for most users that do not have a professional sound card or tape player. Alternately, quarter-inch cable connectors or even RCA cables may be necessary.
Open the Audacity program. Select the "Preferences" option and choose the "Audio I/O" tab. Locate your sound card in the list and select it. Do not select other likely options in the list, including "Microsoft SoundMapper."
Click the "2 (stereo)" option on the "Audio I/O" tab if your audio tape is in stereo. Press the "OK" button to return to the main Audacity window.
Click the input selection button on the Audacity mixer toolbar and choose the "line in" option. This button is probably set to default to "Mic" and will labeled as such until changed.
Click the "File" menu and choose the "Save As" option to specify and name and location for your recording of the audio tape.
Press the red "Record" button in Audacity followed by the "Play" button on your tape player. The tape will be transferred into the computer.
Press the "Stop" button on the Audacity toolbar when the tape has finished playing. Double-click the entire wave file on the Audacity window to select the full tape audio.
Click the "Effect" menu and choose "Noise Removal." Then select the "Get Profile" command. Audacity will analyze the tape audio to identify what audio characteristics need to be enhanced. This will include tape hiss and other artifacts.
Click the "Effect" menu and choose "Noise Removal" again. Then select the "Remove Noise" option. The entire tape audio will be processed and the audio enhanced.
Click the "File" menu and choose "Save" to keep your results.