ok ...

Problem solved...

I changed these settings in the Bios:

by so

-Settings / Windows OS Configuration
--- Windows 8.1 / 10 = "Enabled
--- Windows 7 = "Disabled"
--- MSI Fast Boot = "Disabled"
--- Fast Boot = "Enabled"
---> = Secure Boot Secure Boot Support = "Disabled"
---> = Secure Boot Secure Boot Mode = "Standard"

to so

-Settings / Windows OS Configuration
--- Windows 8.1 / 10 = "Disabled"
--- Windows 7 = "Disabled"
--- MSI Fast Boot = "Disabled"
--- Fast Boot = "Disabled"

is...

IT WORKS!!!