I was fed up of Windows update erasing my grub entries. So I have documented the steps to fix it, the steps which works for me. I hope it helps me when I lost my grub bootloader again.
To fix the bootloader, follow the below steps:
- Boot from a Manjaro Live USB
- Open Terminal
- Type below command:
sudo manjaro-chroot -a
grub-install --recheck /dev/sda