cannot install ubuntu on a dual with windows. Grub won't install

[gwe lem]

Badly removed an old not working ubuntu 16 install (removing partition), boot is crushed. Can't use boot-repair because of path to /cow not found. So tried to re-install a new ubuntu 19 to re-install grub. Grub install failled while install

ProblemType: Bug
DistroRelease: Ubuntu 19.10
Package: ubiquity 19.10.21
ProcVersionSignature: Ubuntu 5.3.0-18.19-generic 5.3.1
Uname: Linux 5.3.0-18-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu8
Architecture: amd64
CasperVersion: 1.427
CurrentDesktop: ubuntu:GNOME
Date: Sun Feb 16 11:25:27 2020
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed only-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
ProcEnviron:
 LANGUAGE=fr_FR.UTF-8
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=fr_FR.UTF-8
 LC_NUMERIC=C.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.