I have decided to upgrade from VMS6 to VMS9. Do I need to remove ver6 befor I load 9? Also, can I continue to edit unfinished projects started with ver 6?
You don't need to remove version 6, but you can. Newer version upgrades aren't dependent on older versions.
You will be able to open version 6 .vf files in version 9 and continue editing them. However, once you save a project in version 9 you'll never be able to open that file in an older version ever again. I suggest you make backup copies of the .vf files, naming them something like '.v6.vf', so that you have them for safe keeping in case you find some insurmountable problem in version 9 and need to go back.