Thank you for your responses, the issue is now resolved. My concern was deleting a project file in explorer having an effect in sonar. I was creating a new project in sonar with a previously used title ie: test, sonar wouldn't allow it. In general computer terms it would ask if I wanted to overwrite it, no such option in sonar. If I delete in explorer the title becomes available again thankfully. One of my concerns was crashing out sonar by incorrect deletion of project files.
I am set to store audio in the named project file and when I delete, all files relevant go. I have tested it and all seems good. Thank you both again for your assistance