Safe to delete old version
I noticed in my Programs I have Firefox 56.0 and 63.0.1...is it safe to delete the older one without worrying about it taking my profile, settings, etc. along with it?
Firefox comes in two or more folders on all computers. They are;
Maintenance: (Programs Folder) <Windows Only> Firefox itself: (Programs Folder) And two folders in the profile of each user on the computer for each Firefox profile for that user.
If you remove the Firefox folder, the user profiles would not be affected.
Did you verify that you actually have two Firefox versions installed in different program folders?
If you only see the two versions listed in "Windows Control Panel -> Programs" then it is likely that the updater didn't remove the entry of the old Firefox version, but merely added a new entry and in that case you will uninstall the current release (i.e. both registry keys point to the same folder). It it possible that one version is a 32-bit version and the other a 64-bit version and in that case the two version are installed in different folders.
- (64-bit Firefox) "C:\Program Files\Mozilla Firefox\"
- (32-bit Firefox) "C:\Program Files (x86)\Mozilla Firefox\"