Windows 10 bootloader not working

Question

I recently uninstalled ubuntu from my dual boot system and since then whenever I start my system

System BootOrder not found. Initializing defaults.
Reset System

appears. Can anyone help? This keep repeating every 3-4 seconds. I can access boot menu and then windows 10 starts but why I can't simply go to windows 10?

score 0 · Answer 1 · answered Feb 28 '19 at 17:48

When you delete or otherwise uninstall Ubuntu from a Windows 10 system the Grub bootloader remains. You need to get rid of it by using a repair disk to get to the command prompt, and type

bootrec.exe /fixmbr

Restart and you should be good. A detailed write up with pics can be found at Uninstall Linux dual-boot

score 0 · Answer 2 · answered Jan 24 '22 at 13:52

This likely occurred due to modifying/removing the boot partition during the removal of Ubuntu:

Boot to WinPE/WinRE
^{(Windows install USB: once GUI loads, Shift+F10 to access terminal)}

Select the OS drive: ^(DiskPart)

DiskPart
Lis Dis
  Sel Dis #

Create boot partition: (if boot partition exists, go to Step 3, else create it)
BIOS:

::# List partitions and select the OS partition:
    Lis Vol
    Sel Vol #
::# Partition should be 100MB formwatted:
    Shrink desired=130 minimum=130
Cre Par Pri Size=128
Format Quick Fs=NTFS Label=Boot
Active

UEFI:

::# List partitions and select the OS partition:
    Lis Vol
    Sel Vol #

::# Formatted size: EFI: 260MB | MSR: 128MB
    Shrink desired=400 minimum=400

Cre Par EFI Size=100
Format Quick Fs=FAT32 Label=EFI
Assign Letter=Y
Cre Par Msr Size=16

Resolve any boot issues:
BIOS:

BootRec /FixMBR && BootRec /FixBoot && BootRec /RebuildBCD

UEFI:

::# With existing bootable EFI partition:
    BootRec /FixMBR && BootRec /RebuildBCD
::# Without existing bootable EFI partition:
    ::# Create EFI directories and enter:
        MkDir "Y:\EFI\Microsoft\Boot"
        Cd /d "Y:\EFI\Microsoft\Boot"
::# Create EFI boot structure:
    BootRec /Fixboot

    ::# If Access Denied error occurs (C: is OS partition):
        BcdBoot C:\Windows /s C: /f UEFI

::# Resolve any other boot issues:
    BootRec /FixMBR &amp;&amp; BootRec /RebuildBCD

Remove EFI mountpoint (if applicable) → Reboot: wpeutil reboot
```
DiskPart
Sel Vol Y
  Remove
  Exit
```

Windows 10 bootloader not working

2 Answers2