The limitation I referred to above is a practical limit since and installation of an operating system will take up a certain amount of space. What you are referring to is a theoretical limit. You can't install 50 Linux system which take up an average of 15GB (minimus) of a 512GB drive. I saw a site years ago where the person installed and booted 145 operating systems from Grub Legacy on one computer with 4 hard drives.

Your boot partition (sda1) is filled up to the hilt.

I foud out how to see install procedure on my laptop screen. The magic word is nomodeset. Click on E before install start. Example opensuse leap os tumbleweed. wen ou see the highlighted menu item installation press E on keyboard \. A light press ! or you have to move severall EEEEEEEEEEs on the screen. This happens if you have intel processor and Nividia videocard. a pitty that iso not comes with that solution bild in.

When the first openSUSE Installation menu appears, move the highlight to "Installation" and strike the "e" key. Then move the cursor to the end of the line (which may be wrapped) beginning with "linu" and ending with "splash=silent" and/or "quiet", and without typing any quote marks, append a space and "nomodeset", then proceed by striking F10 or Ctrl-X to see if black screen and no signal are avoided. If you see a green bar moving across the bottom of the screen that's good. Strike the ESC key to see more information while the boot process proceeds.

I'am happy.

Every one : Thank you for helping, And again Happy Hollidays. See you next year