I always make it a habit to download program files to my DOWNLOADS folder; then, after the program is installed, I move the files from the Downloads folder to the root folder of the program that just installed. Then weekly, me and Acronis, backup the system and validate (always keeping 3 versions of the system backup in case something corrupted the most recent version), plus I always place a copy of the original download files on a 250 ZIP drive (old technology I know, but I have a whack of them and had my ZIP 250 drive transferred to my new custom computer).
To show you how anal-retentive I am, I then use Notepad to create a .txt file with the licence key, which is also stored in the root program folder and on the ZIP 250. It is much cheaper (I am a Scot by descent) than paying for "Extended Download Privileges" for a year. Haven't lost anything yet.
Have a great day.
Regards,
-Phil