Flavio just told me how to find a misplaced sound file. Right click on the wav form and that will bring up the location of the wav file. If you are like me, occasionally I record a file to the wrong location, and this will allow you to find the file with Windows Explorer and move it into the correct subdirectory. Then you can import it back into the sng file.
Alternately, you can use the File > Move/copy to move all of the files into one location. This will preserve all your editing that is in the sng file. the sng is the extension, (myfile.sng) that N-track creates when you save a file. It contains all of the information for you song.
Flavio says that later versions will have a search function to help find misplace files that have not created a wav file that have empty tracks because the file is no where n-Track thought it was.
Bax
Yep. This function has saved my skin on many occasion.