Windows 10 boot error

drqi · August 26, 2016

A few months ago when I "upgraded" to windows 10 I decided I also wanted to add an SSD to my laptop. I left the original hard drive in as well so I didn't even need to sort through all my files and everything seemed to go fine until a while later when I realized that my laptop would only boot if the original hard disk was in it.

Turns out windows left the efi system partition on that hard drive so the SSD couldn't boot windows without the other hard drive. I put up with this bull shit for a while but got tired of it a few days ago and decided to try to fix it.

After probably 5 tries I've successfully created the efi partition and the microsoft reserved partition using diskpart and managed use to bcdboot and/or bootrec to create the bcd store and boot manager and such, but when I try to boot it ends up with a INACCESSIBLE_BOOT_DEVICE error and restarts.

However, it does boot successfully in safemode! But, I can't find anyway to troubleshoot it from here and figure out what the issue is.

I haven't installed any drivers or anything since it was last running correctly so I don't think that's the problem, but I have done crazy stuff including moving over the main partition to make room for the efi and microsoft partitions.

I've googled everything I can think of but almost everything that comes up seems to be people who's computers got broken "upgrading" to win10 and all the answers are just "buy this recovery program" or "reinstall windows" which I don't really want to do because I've gotten this far and its always a huge pain getting all the weird drivers back on a laptop and re-installing all my programs.

Does anyone know how to fix this or things I should check to troubleshoot it?

Naeaes · August 26, 2016

Welcome to the world of personal computers, brah! This has been a thing since the release of Windows 95, I believe. The first OS that was booted by BIOS instead of the user from DOS. That's how boot sectors work. You got one in you computer for all the operating systems. Mess with that or create a second, and you're in for a world of hurt.

Anyhoo. You're on the right track. What you gotta do is unplug the HDD, completely remove all partitions on the SSD, re-create new partition in windows installer and and re-install it. Then after you boot into the new Windows and you have your drivers and all in there, plug in the HDD, delete the old EFI partition and if needed, assign a drive letter for the partition you have left. Fresh new Windows, with the boot secotr on the MBR of the SSD, no other boot sectors and some of your data retained.

Before you start, back up everything from the SSD. Also, you need to have AHCI enabled for this to work. Without it, you need to reboot for the HDD to be recognized. So at that point, you'll be rebooting with two bootsectors so thing can go sideways.