Sorry, I explained that badly.
I have burned - or rather failed to burn, the project; it stopped at 1min 50sec with a Run Time Error message.
The reason I wanted to know if I can save the edits I did using nero whilst creating the project is because 1/ the source files are on a virtual drive, and one of your list of Things To Do Before Trying Again is disabling virtual drives, and 2/ it took me days to do the edits and I want to avoid if possible having to do it all again.
I now understand that I must move the project and the source files from the virtual drive so I can shut it down.
Thank you for your patience. I'm going to read your guides, follow the instructions you gave above, and I'll be back. I hope you won't have given up on me.