Most laptop PCs have very poor quality built in recording. Very occasionally we come across a laptop where microphone recording is not too bad, but that is very much the exception. I’d not be at all surprised if this is just a limitation of the built-in microphone input.
There is a huge topic here about recording acoustic guitar: https://forum.audacityteam.org/t/budget-usb-mic-for-classical-guitar-recording-needed/12367/1