Overview

Because I have a complete and utter disregard for my own free time, I’ve found myself moving Windows partitions around several times in the past month. There are two really fun things about this:

1. Moving Windows partitions is 99% sure to break your bootloader
2. Most search results for my windows pc won't boot please fix are either out of date or trying to sell you shareware Luckily, EFI systems are pretty straight forward in how you get from power button to OS. Basically, when you start your PC it will look for an EFI partition containing boot files. The EFI partition is typically a standard fat32 partition with a special boot flag on it. The boot files can get a little complex, but they’re basically pointers to the actual OS to boot. Knowing this (or if you’re skimming the article because you hate reading), here are the prerequisites:

Prerequisites

1. Your PC must be running in UEFI (not BIOS), which means your disks are GPT partitioned.
2. You have an EFI partition you want to use already formatted and set with the boot flag.

Danger Will Robinson

These instructions only apply to GPT disks and a UEFI system. If you do this while running MBR/BIOS… I have no idea what will happen. We’re going to be messing with disks here, so be careful and don’t blame me if something gets messed up.