Thanks, Stefan, but I tried several of my USB keyboards too, nothing works. This PC seems condemned for eternity to stay in Leap 15.6. I can see the content of the Q4OS Andromeda stick I wanted to install, I even copied the whole thing to my hard drive, but nothing works. In Yast Bootloader I changed boot order, did not work. In Yast Partitioner I wanted to make the stick (sdb) root partition, was not possible, and make it boot partition was not possible. That damn keyboard is just not connected before the login screen … I could perhaps set Bootloader on “no bootloader” in Yast, disabling grub2, but I’m afraid that is not very wise.