Dave, I currently use a full version of Wavepad and have never had any import problems, but the issue with your noise is most likely due to the use of the microphone input. That input has a much different impedance than a speaker or audio input and as a result, the noise may be coming from that difference. If you can hear the audio on your headphones clearly, that is one indicator of the difference or you may have simply not inserted the 3.5mm plug completely into the microphone jack.
Here's a trick you can try. NCH has a sound capture program called 'Sound Tap' that can record any audio playing currently or streaming. Download the program and start it running. Then start your playback in the same manner. You will see the graphics for the two channels on the Sound Tap' as they record showing the volume of the audio. However, if the sound is ok through the headphones, it probably will be okay using the Sound Tap. Then stop the sound tap and open the recording in your 'Music' (default) directory using Wavepad. It should sound okay. Incidentally;the sound tap file will be a number only like '2017-3-15' where the 2017 is the date, and month and day of the recording.
If you still have the noise, Wavepad has some excellent noise reduction filters. I would be happy to try and remove the noise for you if you wanted. I could supply my email address (as long as the sound file was not too extensive.
Good luck.
