Thanks for your interest.
Well, it was UberStudent 4.0. I tried to install it several times from USB and disc, and it was not possible to finish because every time it gave some error (that was strange because with 3.0 all went OK). I worry that the same thing can happen now. BTW, I was really happy when the system updated itself to Epicurus and Heraclitus without to have to reinstall all again!!
On that occasion I installed the OS with the machine in BIOS legacy mode, not in UEFI mode, and the installation program asked me for a special partition for Grub. I don't remember the details. As a result, it was necessary to follow different "boot paths" if one wanted to use Uber Student or Windows, until I ran Boot-Repair-Disc. It reinstalled Grub in UEFI mode, so now one can boot either into UberStudent or Windows from the same menu. I like that and don't want to change it.
If I couldn't install UberStudent this time I'd have to work full with Windows or to use other Linux in the meanwhile, but I like UberStudent