Do yourself a favor and SAVE this download file for future use (like if you get another new computer in a few years) somewhere that you can find it. As it states at that link, the download will not be available after a certain date.
Few years ago I bought Lightroom 5 and get the software on CD. Few years later I bought Lightroom 6 but was not provided on a CD, I had to download it. Kind of upgrade from 5 to 6.
With your link I had to provid Serial N°, password etc of my lightroom 6. And then I had to provide serial N° of my Lightroom 5. Finaly I manage with your link to download a 6.14 version of lightroom. Until the end I was not sure of wish version I was downloading, 5 or 6 🙂
Unacceptable? Assuming you recieved the software on a CD or a download back in the day - Where exactly does your contract with Adobe say that they are obliged to keep a download service for your version available for all eternity?