Windows 10 installation not recognized as bootable?

1

Full disclosure, I posted about this previously here but received no responses, so I'm simplifying the problem here.

I recovered the primary partition on my Intel RST RAID 10 array, but my computer does not see it as a Windows installation and will not boot to it. Furthermore, Windows Recovery Tools doesn't see it as a Windows installation either. I suspect this has to do with the EFI boot partition, but I haven't read very much about this. Is there any way I can repair my Windows install, or should I just do a fresh install? Thanks for your help!

Duck

Posted 2019-05-23T19:00:00.787

Reputation: 13

Possible duplicate of Repair EFI Windows boot sector for recovered RAID 10? Please do not post duplicates. Yes, the problem is that somehow you delete d or corrupted the EFI partition. Booting Windows installation media and going to repair mode should take care of it.

– None – 2019-05-23T19:12:01.223

@GabrielaGarcia As I mentioned in the post, booting Windows Installation Media did not work as it did not recognize the installation at all. – Duck – 2019-05-23T22:49:10.937

@GabrielaGarcia removed original post. Was overly complicated and gained no traction. – Duck – 2019-05-23T22:55:50.090

Answers

0

You can use bcdboot on your Windows repair media. The docs for it is here and it should work regardless of whether or not you have RAID.

I would recommend using this command, but you should read the docs on bcdboot and tweak the command as it suits your system

bcdboot C:\Windows /s H: /f UEFI

Replace H: and C: with your ESP drive letter and your Windows installation drive letter, respectively.

Note: this puts Windows at the top of your boot order, so if you’re dual booting or something like that, use the /p switch.

Varun Narravula

Posted 2019-05-23T19:00:00.787

Reputation: 396

Thanks for the response, I tried to use this command and ran into some issues. I used TestDisk to recover my primary partition, but it seems the ESP partition isn't quite right. There is unallocated space on the drive and the ESP partition is smaller than I think it should be. Any way I can repair that partition or should I just use the command on it anyways? – Duck – 2019-05-23T22:52:31.437

1I would try to move all the files in the EFI partition to a separate drive, delete and recreate the partition using diskpart (the commands create partition efi and format fs=fat32 quick), and move the files back. Unallocated space within the partition means that the file system wasn’t created correctly somehow, so that’s how you recreate it. – Varun Narravula – 2019-05-24T14:18:31.247

When I boot to my secondary OS on a separate hard drive, I am not able to access the EFI partition, it gives me an error. Is there a command I can use to rebuild the EFI partition from scratch? – Duck – 2019-05-25T15:07:48.970

What operating system is it? Please clarify so I can give you more help – Varun Narravula – 2019-05-25T15:08:46.303

Windows 10 Pro 64-bit – Duck – 2019-05-26T19:03:19.197

If you have your Windows installation media, you can move everything off your ESP to an external drive. Format the partition again with Diskpart, and do the same procedure I described above with formatting a new ESP. Otherwise, if you still can’t access your files, use a Linux disk, format an EFI partition with gdisk, and use the bcdboot command I described in my answer. – Varun Narravula – 2019-05-26T19:49:06.827

I started working 40+ hour weeks so didn't have a chance to try your suggestion before, but I got it working today! Thanks for your help. I ended up making an image with Macrium Reflect of the primary partition on the broken install, then reinstalling Windows, then restoring the image, then using the commands you commented to recreate the EFI partition with diskpart. Then I used bcdboot and it worked perfectly. Many thanks! Great answers. – Duck – 2019-06-07T03:50:20.367

Asked: 2019-05-23T19:00:00.787

Viewed: 53 times

Active: 2019-05-23T22:55:17.417