I’m going to mark as solved the thread. Only one more thing.
When I saw that this commands fix the problem, I format the laptop and I made a new installation of Windows and Antergos.
In this scenario, only with the using the final commands (point 4) happened an issue. The second command shows me that the directory didn’t exist or something like that.
As the instalattion was new, I figured that some command that I used in other tries was missing.
So, searching on the thread, I supposed that using this series of commands it would solved:
mount /dev/sda5 /mnt
mkdir -p /mnt/boot/efi # editar: agregó -p
mount /dev/sda2 /mnt/boot/efi
pacman -S --needed efibootmgr # no está seguro de que tiene que hacer esto
grub-mkconfig -o /boot/grub/grub.cfg
grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=grub
And then, continuing with this ones:
mount /dev/sda2 /mnt
mv /mnt/EFI/Microsoft/Boot/bootmgfw.efi /mnt/EFI/Microsoft/bootmgfw.efi
cp /mnt/EFI/grub/grubx64.efi /mnt/EFI/Microsoft/Boot/bootmgfw.efi
With that, the issue was fixed.
Again, thank you very much for all your help!