Did you confirm that this older version is still installed because it is possible that this is only about a leftover (orphaned) uninstall registry key ?

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\

There are still a large number of files in the Mozilla folder.

But is that the same Firefox version as the one you try to uninstall ?

You can check the application.ini file in the installation folder for more detail.

In Windows Control Panel, there is only one Mozilla program listed.

Under the following: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\ There is no listing for Mozilla.

Can I manually delete the program?