multi track recording

im recording a song using rythm guitar on 1 track then lead guitar on another track, problem is when im recording lead guitar because im listening to the rythm while playing so i know where to come in, the rythm gets recorded again over the top of the origional recording making it sound very very fuzzy, is there something im doing wrong here or is this as good as it gets ?

The usual reason (if you are a beginner) is that you have chosen the stereo mix or “what U hear” input in Audacity Device Toolbar instead of the input your guitar is connected to, and/or you not wearing headphones.

If none of that applies, please tell us exactly how you are connecting the guitar to the computer and exactly what input and output choices you have in Device Toolbar.