You can run the installer without deleting files or uninstalling a previous version of the Spine launcher.
I did run the installer at first (Windows 10) without going to Win' settings and uninstalling anything. The installer is '3.7.81', however, after it ran it I opened Spine and the old one came up 3.6.x and didn't ask for an activation code, just ran as usual. So then I uninstalled the old one, reran the latest installer again and this time it started downloading files, installed 3.7.83 which runs fine as the new one. I should mention I didn't stop the first install at anytime, wasn't using any other program and just let it do its thing till it finished. I don't know, maybe it's just me and what happened, a glitch in the Matrix. Anyhoo, many thanks for all your hard work. Appreciated, I think it's great.