Plug your guitar into the digital audio interface using the line cable and the "line-in" port on the interface. Connect the interface to your computer using a USB or FireWire cable. Although most digital audio interfaces now use high-speed FireWire data transfer, some devices continue to implement USB technology.
Power on your computer and open your preferred digital audio workstation, or DAW. Programs such as Logic, Pro Tools, Reason and Record offer users the ability to record audio from plug-in devices such as guitars and microphones directly into the computer. After launching your DAW, open the "I/O settings" and select the audio interface as the preferred audio input device. The interface will now transmit received signals directly into the computer.
Increase the input level of the line-in port on your interface to heighten the sensitivity of the recording device. This will allow the interface to transmit quieter sounds such as finger noise directly to the DAW.
Create a new track in your DAW and arm it for recording. Press "Record" and begin making the desired finger noise on your instrument. The sounds you are making should travel directly through the interface and into the DAW, appearing as a waveform within the software. If they do not, check to make sure that all of your devices are properly plugged in.