Grub2Win is a software developed by David Pickens. Here, I will Provide the offline installer for that software. There are no offline installer in the internet when I writing this article
Features
Supports both 64 and 32 bit EFI as well as BIOS firmware.
Installs to Windows 10, 8, 7 and XP.
Requires just one directory on the Windows C: drive, about 20 MB disk space.
Works with all languages. Boot time help is available in 30 languages.
Simple Windows GUI easily sets up Grub2Win in seconds.
Lets you set your EFI firmware boot order from within Windows.
Preview and customize the 9 included graphic background themes. You can also create and customize your own background themes.
Works with all filesystems including Mac hfs and Btrfs.
Can search for and boot a partition by it's UUID or label. Supports advanced scripting.
Works with both GPT and MBR disks - up to 128 primary partitions per drive.
Supports extremely large (over 40 TB) disks and partitions.
No registry changes.
Automatically generates config files for Windows, Android, Ubuntu, Debian, Suse, Fedora, Manjaro, Mint, Clover and more.
Import config files for all other Linux distributions.
Grub customization is done from Windows - Configuration in Linux is not required.
Includes open source GNU Grub 2.04 boot modules and libraries. Frequent releases and enhancements.
No adware or spyware - No hassles... It just works.