Ubuntu and many other Linux distributions use the GRUB2 boot loader. If GRUB2 breaks—for example, if you install Windows after installing Ubuntu, or overwrite your MBR—you won’t be able to boot into Ubuntu.
The boot sector has been replaced with a non-standard Windows Vista or Windows 7 boot sector. The boot sector is damaged. An earlier Windows operating system has been installed after Windows Vista or Windows 7 was installed. In this scenario, the computer starts by using Windows NT Loader (NTLDR) instead of Windows Boot Manager (Bootmgr.exe).
- Use bootable disk to repair EFI bootloader for Windows 10/8/7. If you are having Windows EFI bootloader problems and unable to boot computer smoothly in Windows 10/8/7, don't worry. Professional partition manager software will support you to create a bootable disk to repair corrupted EFI bootloader without any problems.
- Nov 13, 2012 – Fix the Windows Vista bootloader – Fix the Windows 7 bootloader – Fix the Windows 8 bootloader.warning – Messing with this stuff is potentially dangerous to your PC. I am not responsible for what you do. Option 1 – Standard Bootloader Repair. 1 – Boot from the Windows install or repair CD appropriate to you version of Windows.
- Ubuntu and many other Linux distributions use the GRUB2 boot loader. If GRUB2 breaks—for example, if you install Windows after installing Ubuntu, or overwrite your MBR—you won’t be able to boot into Ubuntu.
- I am having trouble repairing my Windows 10 boot loader. I have tried booting into the Windows 10 installer usb and doing the Repair Start Up there. I have tried the solution suggested here: How t.
You can easily restore GRUB2 from a Ubuntu live CD or USB drive. This process is different from restoring the legacy GRUB boot loader on older Linux distributions.
This process should work on all versions of Ubuntu. It’s been tested on Ubuntu 16.04 and Ubuntu 14.04.
The Graphical Method: Boot Repair
RELATED:How to Boot Your Computer From a Disc or USB Drive
Windows 10 Boot Menu Repair
Boot Repair is a graphical tool that can repair GRUB2 with a single click. This is the ideal solution to boot problems for most users.
If you have the media you installed Ubuntu from, insert it into your computer, restart, and boot from the removable drive. If you don’t, download a Ubuntu live CD and burn it to a disc or create a bootable USB flash drive.
When Ubuntu boots, click “Try Ubuntu” to get a usable desktop environment.
Ensure you have an Internet connection before continuing. You may need to choose a Wi-Fi network and enter its passphrase.
Open a Terminal window from the Dash and run the following commands to install and launch Boot Repair:
The Boot Repair window will automatically scan your system after you run the
boot-repair
command. After it scans your system, click the “Recommended repair” button to repair GRUB2 with a single click.You can choose to use the advanced options here, but Ubuntu’s wiki recommends you not use the advanced options unless you know what you’re doing. The recommended repair option can fix most problems automatically, and you could mess up your system even more by selecting the wrong advanced options.
Boot Repair will begin working. It may ask you to open a Terminal and copy/paste a few commands into it.
Just follow the instructions that appear on your screen. Perform the instructions Boot Repair wants you to and click “Forward” to continue through the wizard. The tool will walk you through everything you need to do.
Restart your computer after the Boot Repair tool finishes applying its changes. Ubuntu should boot up normally.
The Terminal Method
If you’d rather get your hands dirty, you can do this yourself from a terminal. You’ll need to boot from a live CD or USB drive, as in the graphical method above. Ensure the version of Ubuntu on the CD is the same as the version of Ubuntu installed on your computer. For example, if you have Ubuntu 14.04 installed, ensure you use a Ubuntu 14.04 live CD.
Open a terminal after booting into the live environment. Identify the partition Ubuntu is installed on using one of the following commands:
Here’s the output of both commands. In the
fdisk -l
command, the Ubuntu partition is identified by the word Linux
in the System column. In the blkid
command, the partition is identified by its ext4
https://powerupfile894.weebly.com/64-bit-excel-odbc-driver.html. file system.If you have multiple Linux ext4 partitions, you can get an idea of which is which by viewing the size of the partitions and their order on the disk here.
Run the following commands to mount the Ubuntu partition at /mnt/ubuntu, replacing
/dev/sdX#
with the device name of your Ubuntu partition from the above commands:https://powerupfile894.weebly.com/dnc-free-software.html. In the screenshot above, our Ubuntu partition is /dev/sda1. This means the first partition on the first hard disk device.
Important: If you have a separate boot partition, skip the above command and mount the boot partition at /mnt/ubuntu/boot instead. If you don’t know whether you have a separate boot partition, you probably don’t.
Run the following command to reinstall grub from the live CD, replacing /dev/sdX with the device name of the hard disk above. Omit the number. For example, if you used
/dev/sda1
above, use /dev/sda
here.Restart your computer and Ubuntu should boot properly.
For more detailed technical information, including how to use the chroot command to gain access to a broken Ubuntu system’s files and restore GRUB2, consult the Ubuntu wiki.
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Active3 years, 11 months ago
I am having trouble repairing my Windows 10 boot loader. I have tried booting into the Windows 10 installer usb and doing the Repair Start Up there. I have tried the solution suggested here: How to fix Windows 10 boot loader from Windows . I have also tried the fix detailed here: http://www.fixedbyvonnie.com/2013/12/how-to-repair-the-efi-bootloader-in-windows-8/ . Neither of these fixed the issue for me.
The history behind the issue is this: I initially installed Windows 8.1 onto my primary boot ssd. I later repartitioned and installed Arch Linux onto a second partition on the same drive. I then installed Windows 10 over top of the Arch Linux installation. I later removed the Windows 8.1 partition and re-expanded so that Windows 10 was the only OS installed on the drive. (I later added a second ssd with Antergos Linux on it.) This series of installations seem to have left the Arch gummiboot boot loader on the drive, though if I just booted the drive directly it always dumped me directly into the Windows boot loader, so I didn't even realise the Linux gummiboot loader was still present.
I have been trying to get a GPU passthrough setup working [https://www.reddit.com/r/pcmasterrace/comments/3lno0t/gpu_passthrough_revisited_an_updated_guide_on_how/ ] and I couldn't get Windows working in the Virtual Machine, and determined that it seemed to be because of the boot loader. I tried various methods of fixing this (as above), but nothing worked. So I looked at the ssd Windows 10 was installed on and saw that there was still a ext4 partition (alongside of a fat32 partition, which is where Windows had it UEFI boot loader). I deleted the ext4 partition and set the 'boot' flag on the fat32 partition. After doing this, now not only did running Windows in a VM no longer work, but I was no longer able to boot directly into Windows. Now I get a 'PROCESS1_INITIALIZATION_FAILED' error on boot.
Repair Windows 7 Bootloader
I went into the fat32 partition and found that there was still a gummiboot directory. I tried deleting that, but it made no difference. I then deleted all files from the fat32 partition and re-tried the solutions from the first paragraph. Still nothing works. Though I now have 6 different (all non-working) Windows Bootloader entries when I go into the motherboard BIOS.
Is there any way of fixing this, aside from completely reinstalling Windows 10? And, if I have to reinstall Windows 10, is there any way to save the current partition where the actual Windows 10 installation is (as opposed to the EFI/boot partitions) and dump it over top of a new installation? (And how do I remove all of the Windows 10 bootloader entries from BIOS?)
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emacsomanceremacsomancer
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1 Answer
Assuming Windows is installed to GPT disk. https://powerupfile894.weebly.com/microsoft-office-corporate-discount-program.html.
To successfully boot Windows 10 (also Windows 8.1/8/7) on UEFI firmware you need exactly 3 partitions on a GPT styled disk:
- EFI System partition (usually 100 MB - 500 MB)
- Microsoft Reserved partition (exactly 128 MB)
- Windows partition (at least 20 GB for 64-bit Windows)
Eventually you could have a separate 'recovery' partition.
The presence of first three partition mentioned is mandatory or else Windows cannot boot.
The command to fix BCD + boot loader + boot manager and write a boot entry in NVRAM is bcdboot.exe -
where N: is Windows partition and Z: is EFI System partition. (Later you have to fix recovery loader separately using ReAgentC.exe command.)
You can use also bootrec.exe command from recovery environment to fix booting (not always successful but fixes also recovery loader).
No need to say that you have to boot Windows installation/recovery media (USB/DVD) using EFI boot.
UEFI booting does not use MBR and partition boot records for booting but it may help to rewrite MBR (should be a protective MBR on GPT disk) using bootsect.exe command in case MBR was tampered by Linux install. Windows does not like 'mixed' MBR format on GPT disk.
Reference: Repair Windows BCD on UEFI and BIOS
Hope this helps.
Windows 10 Boot Loader Repair
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