Because laptop did not recognize my linux boot usb-stick i changed from UEFI to legacy mode and the installation went through without any problem.
At the end grub was in place but the windows installation was not listed. This is, because windows does not support booting.
The problem: If i switch back to UEFI the linux installation did not start anymore.
- Change to UEFI and boot with a live linux
- Install boot-repair into the live linux
sudo add-apt-repository ppa:yannubuntu/boot-repair sudo apt-get update sudo apt-get install -y boot-repair
- Then run boot repair
- Follow the instructions on the Boot-Repair homepage (s. above)
- Enter the commands of the following popus:
And after removing the live CD i got an boot grub menu, where windows was in place and working (and the Ubuntu Linux worked, too ;-)