Remove Grub and revert to Windows Bootloader

tl;dr: How do I remove grub from my laptop and revert to the Windows bootloader?

I installed Manjaro on my laptop alongside Windows with an encrypted linux partition and grub bootloader. So I type the partition password after the bios screen and before grub displays.

I’ve since bought a desktop and installed Manjaro on that. I’m about to travel, and need to revert the laptop to use the Windows bootloader. I can then use a utility to merge the recovered disk space into the Windows partition (which is my main objective).

I’ve searched this forum and Googled. I’ve found a few differing approaches but I wanted to get your advice first.

Thanks…

Repair Windows …

That’s tricky and requires an OEM Windows live-USB; Windows live-USB isn’t available to public. Windows recovery drive won’t do that.

@linusvanpelt , I suggest to remove the Manjaro GRUB based on https://askubuntu.com/questions/63610/how-do-i-remove-ubuntu-in-the-bios-boot-menu-uefi

It’s a post for Ubuntu, but the method is applicable to any GNU/Linux distro. You just need to find “Manjaro” instead of “Ubuntu”. Careful not to delete the “Windows”.

After that, restart the system (now Manjaro GRUB isn’t there and you cannot boot to Manjaro, but Manjaro partition is still there), go to the BIOS setup, and make sure the Windows bootloader is at the first boot order.

Boot to Windows, then use Windows native partition disk utility to expand your Windows NTFS drive to override the Manjaro partition.

Enter the firmware and locate the boot options page

Then set the Windows bootloader as the first - on some systems you may need to enable secure boot otherwise Windows refuse to load.

assuming you have a UEFI setup;
not all firmware allow you to change bootloader order, in that case resort to changing bootloader-order using efibootmgr;

first type;

$ efibootmgr
BootCurrent: 0003
Timeout: 2 seconds
BootOrder: 0003,0002,2001
Boot0000* UEFI Onboard LAN IPv4
Boot0001* UEFI Onboard LAN IPv6
Boot0002* Windows Boot Manager
Boot0003* manjaroSSD
Boot2001* EFI USB Device

the current bootloader-order is given as; BootOrder: 0003,0002,2001
alter such that "Windows Boot Manager"comes first using;

sudo efibootmgr -o <new boot-order sequence>

ex: for the above case it would be
sudo efibootmgr -o 0002,0003,2001

That’s not actually correct. Windows ISOs are available at https://www.microsoft.com/software-download/windows10ISO

And a guide to write the ISO to USB

You can also repair the Window bootloader with Window command line:

  1. bootrec /fixmbr
  2. bootrec /fixboot
  3. bootrec /scanos
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Ok, I didn’t write it properly. I meant the Windows 10 preinstalled within the sold laptop or desktop by OEMs. OEMs usually provide a software to create their own version of Windows 10 installation live media, but you need to contact the OEM and it’s usually not easy to get it.

The link is suitable for someone who wants to install Windows 10 on their own. Like someone buys an empty desktop machine and wants to install Windows 10 on their own. You’ll pay for a Windows OS twice if you do this step when you already have a machine with OEM pre-installed Windows. OEM Windows license is different from normal user Windows license.

Overall, you’re right that the Windows ISO is available to public. Unless you know something I don’t know :wink:.

If you want to use the Windows iso, which is available in the internet, then you only need the Windows key to activate.

License is different but ISO images are the same. If you have Windows preinstalled, you can safely reinstall Windows from those images (without paying anything). You have to use the right ISO version, of course: Home, Pro, Education, …

If Windows 10 have been already been installed on the machine, no license key is needed. On one hand OEM machines have Windows key stored in the computer’s ACPI tables. On the other hand Microsoft takes a fingerprint of the system at the first activation (and stores it in it’s servers), so after reinstalling, Microsoft will recognize the fingerprint and will activate Windows without a key.

The Windows key is stored in the UEFI Bios (I don´t know the precise location).
And then Windows can be activated.

Which Windows version do you have ? Home or Pro ?

You can reinstall Windows at any time - using a downloaded image from Microsoft.

As part of a part time job I have often reconfigured new laptops from various OEM vendors.

Most of them is bought cheap from warehouses and comes preloaded with Windows S and to make it a normal Windows one has to activate it using a Microsoft account as they call it.

I don’t want to go through that process so I usually download an ISO - write it to USB and reboot the system - thus doing a complete reinstall - finally I boot - use hotkey to switch into sysprep mode and run a decrappifier script which removes everything - including the store.

Then exit sysprep and reboot - bang - a completely pristine Windows without all the usual crap.

Then it is loaded with a new user account and installed with SQL and a single company app.

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OP does not need to reinstall proprietary OS or worry about license keys

A live ISO is only required to use the Recovery Environment to replace GRUB. Any ISO for proprietary OS v7 or later has these tools. Some third-party repair/rescue ISO also have boot repair tools

Current online clickbait titles suggest there must be > 10 ways to leave your Linux

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And you won’t believe number 9 is so easy!

? … well I didn’t suggest to reinstall Windows, that’s just an overkill solution for the OP’s question …

That’s a different topic I was talking with @cfinnberg and Bogdan.

I have bought a new Laptop with Win10 Home preinstalled.
I had to install Win10 Pro with a DSP license for ~128 €.

Downloading an ISO might not be needed If the WinRE partition nvme0n1p4 is still viable
Unencrypt boot partition and reconfigure grub - #5 by linusvanpelt

If you have a Windows license, then the keys/license are also stored in a Microsoft account.

Also, doesn’t the system automatically recognize the key if Windows was activated previously in that system?