Can't boot into Windows after 'upgade'

[BH1983]

Hi guys,

I've opened up my PC today to install new fans onto my case and radiator as well as swap out an SSD for a secondary m.2 and now I can't boot into Windows, I just get a message saying:

"Reboot and select proper boot device or insert boot media in selected boot device and press a key"

I didn't touch my primary boot m.2 during the process, and when I installed the secondary m.2 I made sure that there was no HDD plugged into SATA port 1 or PCI slot 4 as per the MB manual.

When I boot up and go into the BIOS all of my drives are listed in the status page, and I've confirmed that my primary m.2 drive is selected as boot option 1 with all other options disabled, and the primary m.2 is also selected as boot option 1 under BBS priorities.

I've tried loading optimised defaults in the bios and clearing the CMOS, neither of which helped.

Can anyone offer any suggestions on how to fix this?

EDIT: This is really strange, I've just plugged the SSD that I took out back in and the computer booted up! But the OS is definitely on the primary m.2 drive so why would plugged the old SSD back in fix the issue??!

 

[EsaT]

You have made the mistake of installing Microsoft OS with two drives attached at that time, am I right?
Being the **** ups they are, Microsoft still don't know how to make proper OS installer and it istalled necessary system partition to that other drive.

Unless you want reinstall there are things to try manually/with tools.
http://woshub.com/how-to-repair-deleted-efi-partition-in-windows-7/
https://www.easeus.com/partition-ma...ted-efi-boot-partition-in-windows-10-8-7.html
https://www.diskpart.com/windows-10/missing-efi-partition-windows-10.html
Not sure if you could shrink partition from main drive and then make necessary partition after that.

And if installing always have only intented target drive attached when installing Wintoys.
You just can't trust MS to do proper job even if you had Elephant gun aimed at their nose.

 

[pc-guy]

Did you migrate your OS from one drive to another at some point?

anyway plug your other drive back in you should be able to boot into windows and use the aforementioned tools to consolidate the boot partitions to the OS install drive.

and also create a recovery media once booted into windows with a usb stick. This will enable you to boot off the usb if it still doesn’t work and repair the boot partition