When you download a file for installation, the recommended practice is to save the file to disk, and then install from the saved "install file." (This gives you a chance to inspect with your AV before you actually "open" it, among other 'reasons given.')
While I understand that we don't always follow the recommendations, it's fairly common for a "direct install from web" to download the install file and then just "trigger" the installation from the file after it's already on your machine. This avoids mangled installation due to an interruption in your web connection, since the actual install doesn't start until you've successfully completed the download.
It is possible that your old version has an "install file" that was left there after stuff was "expanded and applied," if you still have access to the old installation. It would usually be a .exe (self extracting zip?) or a plain vanilla .zip or .cab. While some programs will delete the original, it is quite often just "left laying around."
No guarantees here, but it might be worth looking on the old disk?