Instrument trees can get lost. This may help in getting them back.
The standard files that ship with NoteWorthy Composer as of version 2.51 are:
They have not changed since version 2.0, so any back-ups of these files should work.
Step 1: Find the above files and move them to a dedicated folder.
Step 2: Tell the NoteWorthy Composer program where they are:
If you can't find any copies of the files, contact support@noteworthysoftware.com as outlined in: NoteWorthy Composer - Support and Help (http://www.noteworthysoftware.com/composer/support.htm)
The download from the topic: General Midi.nwcitree (https://forum.noteworthycomposer.com/?topic=5538.msg57886#new) may be of use if the standard files cannot be found.
The files are probably still in the program folder. There is a bug in Tools, Options, Folders that causes this. We have been working on an update to correct this.