In your program menu (start menu ) you have your Steinberg folders for C8 and 8.5 ,wel inside there are your User data folders and if you use the windows explorer you can copy and paste your settings from the C8 User folder to the C8.5 folder , it’s simple 
I wouldn’t. You might run into some compatibility issue later on where you want to open something in 8. Besides the install doesn’t use that much space, and HDDs are big now-a-days. I even leave it on my SSD which is much more space limited (although I do put the larger VST sound data files elsewhere for all versions).
I managed to copy the project templates and some other settings manually, but copying the key commands xml doesn’t do anything… What am I missing here?
EDIT: Gave up and just copied/overwrote everything like this: Cubase 8.5 - Review, New features, tips and tricks and tutorial - YouTube
Thank you . I will keep it in case then.
Let’s enjoy 8.5. Good luck all
If you’re on PC here a video on how to do it: Cubase 8.5 - Review, New features, tips and tricks and tutorial - YouTube
What you actually mean to be more spesific is.
You copy Boot C: > USERS / “your name”/ AppData/Roaming/Steinberg/Cubase 7or 8 (or whatever version you need the presets from )
all those files in that folder over to >
C:USERS/ Your name / AppData/Roaming/ Steinberg/Cubase 8.5
and overwrite the ones if asked to overwrite
Is that what you mean ?
NO , read what i wrote .
NO ,Thats the long way around it
Yep but its the same folder content to be copied over.
Yes The same folder content but the quick way
Yep !! 
Hi,
My configuration of cubase 8.5 disappeared after an intrusion of steinberg asking me to register(record) on-line
(i am already registered)
Idem with cubase 7.5. one year ago
Know you how recuperer my config
Thanks