Windows 10: System booting from wrong drive after installing new parts

So I was booting Windows 10 from a drive labelled C: and all was well and good.

Then I changed some parts around in my computer. Lo and behold, my computer is still booting the OS on C:, but from an unlabelled UEFI system partition on an external hard drive. Wat.

I checked C:\boot, and there's nothing there. Startup repair does nothing, since it's properly booting after all (from the wrong place).

I need to move this computer around, so leaving it the way it is is not an option. I've tried exporting the system bcd and putting it in C:\boot and marking the partition as active, but the bios still won't recognize the drive as bootable, so I'm assuming my MBR is toast. I'm also pretty sure bootrec is acting on the mysterious external system partition by default when I try to repair the MBR.

I won't ask for a magic solution, since this is a pretty weird situation, but do you have any ideas of things I could try, or tools that would fix the MBR on the correct drive, or restore the stuff that should be in C:\boot by default?

Thanks,


:)

 

Windows 10 installation fails

There is no existing operating system as brand new machine.

Nothing wrong with Windows 10 media as if I remove 4 hard drives it installs to SSD on its own with no problem.

So why is it putting part on SSD and part on Hard drive and changing from GPT

 

Windows 10 usb reboots into installer

Hello microsoft community

I'm having a problem with my new pc, where i am trying to install windows 10.

I made it boot from a usb, and then went to the part where you select the disk to install windows to, i selected that and it started installing. A few minutes later it started rebooting, but booted into the installer again. Where it was at the first step.

I think something went wrong, so i went into the boot menu, and saw that it had added a new drive called "UEFI Hard Disk: Windows Boot Manager (P0: Samsung SSD 850 EVO 250GB)." It was set to boot from the usb, so should i switch it to the new drive?

 

Unfortunately, not knowing what parts you moved around makes it difficult to do a long-distance diagnosis but generally it doesn't take much to inadvertently plug the drive cables into a different controller port on the motherboard from what is was on when the OS was installed. When having such problems it is good to first unplug anything not needed such as external drives then try again.

 

A complete screen shot of disk management will help. Be sure to widen the columns so we can see all the information in them:
Disk Management - How to Post a Screenshot of - Windows 10 Forums

 

I've attached the disk manager screenshot, and what I changed was the motherboard (and everything else except the disks).

I managed to write a new MBR with bootsect, and my BIOS sees it as bootable, but it just gets stuck in a restart loop (just an underscore is displayed, no debug info).

The main remaining problem in my mind is that c:\boot is empty.

I have tried removing all other drives, but it won't boot without the external one.

 

Hi,
Here's a relatively painless way to correct partition problems:
A Couple Questions About Partitions - Page 3 - Windows 10 Forums

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That looks good. I'll try it, and if it works, I'll mark this as solved. Thanks!

 

Good luck. Let us know how it goes. *Smile