Hello RbaBuilder and welcome to the forum!
The gcode output file selection can get a bit confusing.

The first time you generate gcode it will prompt you for a file name.
This gets stored in the machining options for the current drawing.
The next time you generate gcode, it knows the output filename so doesn't prompt again. It will display an overwrite warning if the files exists.
To change the filename, select the 'Machining' folder and look in the properties for OutFile (under destination). You can type the new filename in directly here or there is a [...] button after this to bring up a file browser dialog.
One other important point. If you right click on a machine op and select 'Create GCode File', it will generate a gcode file from just that one mop. This can be handy (if you are aware of it).
I hope this helps.
I created a GCode and saved it to the 3.5" floppy so I could take it to my machine.
Now when I try to create GCode - it tries to save it on the floppy drive. The program doesn't give me any option to change folders back to the C: drive.
I think I will just reinstall it for now.