Windows 10: How do I restore w10 bootloader? dual boot with ubuntu on separate hdd

So I am looking to REMOVE ubuntu, but right now, my system uses Grub to boot into windows or ubuntu.

Ubuntu is installed on a hdd, w10 installed on a ssd. I BELIEVE that they are both efi installs (cannot remember which way I did it) because both disks are GPT format. On the other hand, if I select UEFI only for boot options in my bios, only "ubuntu" boot device is available on the F12 screen.

I've tried the w10 repair usb, it was not able to auto repair it, I've also tried:
bootrec /FixMbr
bootrec /FixBoot
bootrec /ScanOs
bootrec /RebuildBcd

And the scanOS returns with "0 windows installations found" and rebuildBCD fails bc of this.

I've also tried easyBCD and clicked "write MBR" but all it did was create duplicate "ubuntu" boot devices in the f12 screen.

The only way my ssd shows up as a boot device is if I have legacy mode on in the bios, then it shows up as: "P0 samsung 840..." and fails to boot into windows, can't remember the error code but I've seen it a lot for this issue on forums.

I have two other threads started on r/ubuntu and r/techsupport I've also attached an image below of my disk manager in w10 if it's of any help:





:)

 

How do I restore dual boot capability after Windows 10 clean install removed it

My computer was dual-boot with Windows 7 boot partitions on two separate drives. After upgrading to Windows 10, the dual boot provision worked fine. However after a clean install of Windows 10, dual-boot capability is no longer available. The boot partition
for the remaining Windows 7 syBistem is intact. Only the dual boot option is gone.

I tried the changing the default operating system under System Properties/Advanced/Startup and Recovery, but the only choice is Windows 10. Windows 7 isn't a option. I'm guessing that the clean Windows 10 install wiped out access to the dual-boot menu.

Thanks.

Bill

 

how do i Create another HDD?

Hi Devin,

As you trying to Dual boot Windows 10 with Ubuntu, I suggest you to refer to the below articles and check if it helps.

Articles for reference.

Windows Dual Boot:

https://help.ubuntu.com/community/WindowsDualBoot



Installing Windows 10 alongside Ubuntu?:

http://answers.microsoft.com/en-us/windows/forum/windows_10-win_upgrade/installing-windows-10-alongside-ubuntu/443bab47-11e8-47ea-a38b-24f2afdfd1fa



How to dual boot Windows 10 with previous versions of Windows:
How to Dual Boot Windows 10 with Other Versions of Windows, macOS and Linux



Keep us informed to help you further.

 

Will Windows 10 boot up correctly, if you disable disk 0 (remove the data cable or disable it in the bios)

If not, then:

- boot the computer using the Windows 10 installation media
- press SHIFT+F10 to bring up the command prompt
- run the following command

bcdboot c:\windows

bcdboot <source>

source - Specifies the location of the Windows directory to use as the source for copying boot files.

UEFI mode: BCDBoot copies the boot files from the Windows 10 partition to the EFI System partition and creates the Boot Configuration Data (BCD) store in the same partition.

EDIT: Look at post #24

 

I have unplugged that drive and the "ubuntu" boot device is still the only one that will show up. When I try to boot from that, it brings up a black screen with white text saying something about limited input to grub. And that's as far as I can get.

I will try your suggestion tonight and see if it works.

Side note, I'm looking to do a VFIO passthrough in linux. Basically I will install linux then create a VM within that and run win10 on that which I will use for playing games. my question to you is, if I were to resolve the problem at hand and create a system image of that ssd that has only windows on it, could I wipe that ssd in the future if need be and restore my windows 10 state with that sys image, with all documents and programs, and bootloader intact?

 

Will this still work even though when I run bootsec /scanOS the cmd prompt says "0 windows installations detected" ?

 

More info:

bootrec /fixmbr (writes a MBR to the system partition but does not overwrite the existing partition table)
bootrec /fixboot (writes a new boot sector to the system partition)

Note that bootrec /fixmbr and bootrec /fixboot commands are not needed at all, if the hard drive has a GPT partition style. UEFI mode do not use boot sectors on the hard drive and do not require active partition to be set.

bootrec /rebuildbcd

The bootrec /rebuildbcd command will search for Windows installations not included in the Boot Configuration Data (BCD) and then ask you if you'd like to add one or more to it.

BCDBoot Command-Line Options

"Repair the system partition. If the system partition has been corrupted, you can use BCDBoot to recreate the system partition files by using new copies of these files from the Windows partition."

 

EDIT: Look at post #24

 

Thank you very much Avodcado. I will try all of this tonight after work.

 

Did this and after the bcdboot command I got "failure when attempting to copy boot files"

 

Computer wouldn't boot after cloning to SSD

See the above thread. I'm thinking you don't have the partition type for what you think is the EFI System Partition set correctly. Under partition type or volume info you should see listed as System, not Hidden:

My EFI System Partition is Volume #4 which is Partition #2 on my Drive #0:

Code: Microsoft Windows [Version 10.0.14393] (c) 2016 Microsoft Corporation. All rights reserved. C:\windows\system32>diskpart Microsoft DiskPart version 10.0.14393.0 Copyright (C) 1999-2013 Microsoft Corporation. On computer: MAIN-DESKTOP DISKPART> select disk 0 Disk 0 is now the selected disk. DISKPART> list volume Volume ### Ltr Label Fs Type Size Status Info ---------- --- ----------- ----- ---------- ------- --------- -------- Volume 0 E DVD-ROM 0 B No Media Volume 1 F DVD-ROM 0 B No Media Volume 2 C WIN10PRO NTFS Partition 111 GB Healthy Boot Volume 3 Recovery NTFS Partition 450 MB Healthy Hidden Volume 4 FAT32 Partition 100 MB Healthy System Volume 5 D Storage NTFS Partition 926 GB Healthy Volume 6 RECOVERY FAT32 Partition 5128 MB Healthy DISKPART> list part Partition ### Type Size Offset ------------- ---------------- ------- ------- Partition 1 Recovery 450 MB 1024 KB Partition 2 System 100 MB 451 MB Partition 3 Reserved 16 MB 551 MB Partition 4 Primary 111 GB 567 MB DISKPART>[/quote]

 

Did as instructed in that link. When I boot up it shows a black screen with "reboot and select proper boot device or insert boost media in selected boot device and press a key

Any ideas?

 

I would make a bootable USB flash drive or DVD of Kyhi's Recovery Tools:
Windows 10 Recovery Tools - Bootable Rescue Disk

Boot the computer from that. Run Macrium Reflect. Under the restore menu is a utility to Fix Windows startup problems. See if that fixes it for you.

 

I'll try that tomorrow. Tonight I followed some advice I found somewhere (forget now because I've got posts on multiple forums) and I get all the way to the end and got an error. Here is a screenshot of the cmd prompt showing what I did:

cmd prompt screenshot

picture won't upload for whatever reason so I place a link

 

Hopefully Macrium Reflect works for you. The only other thing I can suggest is use Macrium Reflect to make an image of your current Windows 10 OS partition (if you really want to keep it) save the image to a second hard drive (internal or external). Boot from Windows 10 installation USB flash drive or DVD, wipe the drive by deleting all the partitions on it (if you have a data partition, you can leave that one). Select the unallocated space to install Windows 10 to and do a clean install.

Once the clean install is done, you will have a good EFI system partition. Then you can restore the OS partition from the backup image over the top of the newly installed OS partition. Run the Fix Windows Startup utility again, and you should be good to go.