I am a long time happy user of the free version. On my Windows 7 x64 PC I had version 5.6, 5.7 and 220.127.116.111 installed.
Tried to install 18.104.22.1686: it failed on error 1316. I followed the instructions on your website and managed to uninstall all 3 previous versions with Microsoft Fixit (sort of…). After nearly two hours, I had the installations removed from the configuration panel. I checked and found that C:\program files(x86)\Quest Software had still the directories and lots of files for 5.6, 5.7 and 5.8, but unusable.
Now to install the new version. It attempts to remove an older version and fails with an error (no number) that translates from French into something like “This action is only valid for products already installed”.
So, to sum il all, no way to get 22.214.171.1246 to install on this machine.
Thanks for your suggestions.