How to reinstall GRUB bootloader on the Master Boot Record (MBR) in rescue mode

Solution Verified - Updated 2026-06-29T21:03:22+00:00 -

Issue

How to reinstall grub2 into the MBR on Red Hat Enterprise Linux?
Why does my Red Hat Enterprise Linux system drops to GRUB rescue prompt on boot?
I had to restore my system and data partitions from tape after a crash. Why does my Red Hat Enterprise Linux system only shows a black screen after POST?
I reinstalled Windows on my server and now I can no longer boot to Red Hat Enterprise Linux.
On attempting to reinstall grub I get the following error "Error 5: Partition table invalid or corrupt"
When I do grub-install I get error as "Error 12: Invalid device requested"

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