Thank you Phil, for your post.
I had run, yesterday, the HX Edit installation package.
Actually now, starting the PC, there"s two sessions, one for administrator, the other for users.
In the administrator session, helix is well installed (Helix unit connected to HX Edit) but the updater doesn't work (message : http error).
In the user session, Helix unit isn't recognized by HX Edit, although the Helix unit appears as an identified peripheral.
So, the set up of my PC seems concerned.
For now, it's difficult to know what parameter to modify.
Thanks for any advise