Windows operating systems have a tendency of installing their own bootloader on every installation. However, this is not the problem, the problem is that the bootloader only recognizes other Windows systems but fail to boot all other present systems. GRUB is the short-form of GNU Grand Unified Bootloader. This refers to a multiboot specification software which allows the user to boot one of the multiple operating systems that are installed or select a specific kernel available on the partitions of a particular operating system.
When one installs Windows it overwrites the current MBR (Master Bootloader Records) in this case GRUB such that when you start the computer, it will automatically boot to Windows. So, how do you restore GRUB after installing or reinstalling Windows? Here are some ways you can use to recover GRUB.
You can get the necessary software, download and burn the Fedora Rescue ISO for the Fedora version that you have installed. After you have burned your Fedora Core Rescue disc, use it to reboot your system and type the command prompts to install GRUB and then reboot and there you have it.
You can also download and install EasyBCD and other tools on Windows to help you recover GRUB.
You can use a live CD ie. Ubuntu to reinstall the lost GRUB. Afterwards, you can remove the live CD and boot into GRUB.
> Begin by inserting your Ubuntu CD, then rebooting your system and setting it to boot from the disc into a live session
> Installing and running the boot repair should be next
> Select recommended repair
> Reboot your computer and now the normal GRUB menu is supposed to be seen. Should it fail, hold left shift when booting to select your operating system
Alternatively, you can open a terminal by selecting the Ubuntu logo or using the Windows key on the keyboard and type ‘Terminal’ and click on what comes up. You are prompted to type commands to reinstall to MBR of a working system then install GRUB and reboot your system.
You can also use the Ubuntu alternate CD
> Boot the system from an Ubuntu alternate disk
> The splash screen comes up, in the prompt type rescue and press enter
> Choose your language and location and keyboard layout as you would in a fresh install
> Enter a hostname or leave it with the default.
> Select the root partition which Ubuntu is on.
> Install GRUB through the Terminal described above.
You can achieve the same results by going to the control panel, update and recovery, go to recovery, boot to UEFI, select boot from device and boot to the Ubuntu partition.
Use your computers boot menu at start-up by pressing ESC button then run a command to install GRUB in the terminal.
These are some of the methods that you can apply to recover GRUB after installing or reinstalling Windows operating system.