Grub will not install on 18.04 Dell Latitude E7450

[Muhammad Alfa]

first grub did not launch on dual boot with Win 10. tried boo-repair which sort of hanged on the terminal and nothing was happening during purge.
shut down and tried to reinstall ubuntu again and the grub failed to load again.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubiquity 18.04.14.12
ProcVersionSignature: Ubuntu 5.0.0-23.24~18.04.1-generic 5.0.15
Uname: Linux 5.0.0-23-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.7
Architecture: amd64
CasperVersion: 1.394
CurrentDesktop: ubuntu:GNOME
Date: Thu Oct 24 13:17:48 2019
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity quiet splash ---
LiveMediaBuild: Ubuntu 18.04.3 LTS "Bionic Beaver" - Release amd64 (20190805)
ProcEnviron:
 LANGUAGE=en_NG
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_NG
 LC_NUMERIC=C.UTF-8
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (probably fresh install)