I have the same problem of converting an FTW file to a Gedcom, or more particularly, Legacy file.
I downloaded the viewer as suggested, but it turns out that the FTW file must have been created in a later version because the viewer can't help me.
I have instructions that tell me how to get the person to export from their program to a gedcom, but they don't seem to be working. The file always comes with the extension .ftw. The person I am dealing with is in another state and they are also not that computer savvy. They may just not be following the instructions 100%.
Any other options available before we drive each other crazy trying ?