Installation of Ubuntu on a Windows desktop

**alan44zz** · September 15th, 2024

Hello,
Sorry to post such probably stupid questions but...

I have a desktop running under Win10 and want to install Ubuntu24 on it, on a dedicated HD.
In the computer U have 6 hard disks, all used by the Windows system, MBR partition style and NTFS formatted.

I made a bootable USB disk with Ubuntu, and have 3 questions:

1- About dual boot. As I understood, GRUB will manage the boot. Will it work correctly with the MBR partition style for all disks ?

2- Will the other disks be concerned by the Ubuntu installation ? I remember that, maybe 15 years ago, I tried to install a Linux OS in a Windows desktop and it "initialized" ALL disks inside. Data was lost... I can of course physically unplug the disks, but...

3- Will I be able to use the other disks in the computer, currently used by Windows, with Ubuntu ? Data only, not software of course.
I read online that is it possible but the exact question is to know if, after using them with Ubuntu (for example writing some data), can I use them again with windows, with all "new" data written by Ubuntu, usable ?

Thank you!

**ajgreeny** · September 15th, 2024

As your Windows 10 is unusually installed in MBR/UEFI mode you will have to ensure that you boot the USB install drive in the same MBR mode which will then install Ubuntu in that mode.

Both OSs must be the same mode for grub to work and offer both at boot.

**grahammechanical** · September 15th, 2024

I suggest that for safety's sake. Disconnect those hard drives that you use for Windows. Have just the har drive that you want to put Ubuntu on. After installation of Ubuntu replace those Windows drives. Then load into Ubuntu and open a terminal and run this command:

Code:

sudo update-grub

Watch the printout. Grub should identify the Windows operating system and when to bot you should get a Grub menu with options to load either Ubuntu or Windows.

This forum thread provides useful information

https://ubuntuforums.org/showthread.php?t=2491292

You may also need to install a special driver to read/write to NTFS drives.

This might be too much information. At least it shows the package you need is ntfs-3g

https://manpages.ubuntu.com/manpages...ntfs-3g.8.html

Code:

sudo apt install ntfs-3g

Regards

**yancek** · September 16th, 2024

About dual boot. As I understood, GRUB will manage the boot. Will it work correctly with the MBR partition style for all disks ?

It can if you boot and install correctly. If you are very inexperienced it would probably be best to disconnect your windows drives. If you boot the Ubuntu install USB and from a terminal run the command below, it will tell you if you have a gpt Partition table or dos. I expect it will be a dos drive if windows is an MBR install which as pointed out above, is pretty unusual for the windows you are using. Must have pretty old hardware. If it is dos, then boot and install with your BIOS set to Legacy/CSM for the sake of simplicity. If you do an EFI install of Ubuntu on one physical drive and have a Legacy install of windows on a separate physical drive, the Ubuntu Grub should still boot windows. This works for me but for the sake of simplicity, I would install/boot all in the same mode. You need to know which drive you are installing to and know Linux drive/partition naming conventions.

Code:

sudo parted -l

As far as accessing and overwriting other disks, if you know the drive on which you wish to install Ubuntu and are familiar with Linux drive/partition naming conventions it should not be a problem. Installing Ubuntu properly to a specifically selected drive will not affect other drives. Maybe you did an LVM install without knowing what it did in your previous attempt.

You should be able to write data to windows partitions with a windows filesystems but you are not going to get a guarantee from anyone.

**alan44zz** · September 19th, 2024

Hello!

Well, I installed Ubuntu, ont its dedicated HD, no problem. Just the dual boot doesn't work.

In the (legacy) BIOS I put first ubuntu disk, it boots directyly into Ubuntu. No Grub menu.

In the (legacy) BIOS I put first windows disk, it boots directyly into Win 10.
I then here tried to add a boot entry with EasyBCD : Grub2, it detected the Ubuntu path (attached picture)
When I reboot, I get the "windows choice" between Win10 and Ubuntu.
If I choose Ubuntu, it stops at the screen shown in the second attached file.
What must I do if I want this first option ?

In fact as my goal is to get rid of Windows, I think I should put the Ubuntu disk at first in the BIOS boot section, and try to get Grub offer the option to boot in Windows too. So later if I remove the WIndows disk, all will work smoothly.
In this option as told above, the box boots directly into Ubuntu, no Grub menu.
What must I do if I want this second option ?

Thank you

**alan44zz** · September 19th, 2024

According to the current situation, seems there's something wrong

**ajgreeny** · September 19th, 2024

See Boot-Repair in my signature below and follow the instructions there to run the Boot-Info-Script.

Do not run the default repair just yet but simply copy back here the pastebin link you get which will show us a lot more about your system.

**yancek** · September 19th, 2024

So you have verified that windows is installed in Legacy mode and Ubuntu is also installed in Legacy mode on a different physical drive, correct? What you describe is expected behavior as Grub in Ubuntu no longer probes for other operating systems by default. Boot into Ubuntu and using a text editor and sudo, edit the file /etc/default/grub to add the line below:

GRUB_DISABLE_OS_PROBER=false

If that line exists in the file make sure you do not have # at the beginning of the line and if you do, delete the # character. Save the change and run sudo update-grub and you should see output for other operating systems detected if any are found on the connected drives. Watch for a windows entry and if you see one, set the Ubuntu hard drive to first boot priority in the BIOS.

Verify that Ubuntu is not UEFI. Is Ubuntu on a GPT disk? You can get this information with the simple command below which will List the partition info:

Code:

 sudo parted -l

If both systems are Legacy, I would expect EasyBCD to work but it won't work if Ubuntu is UEFI and I don't know how or if it will work on a GPT disk so doing this check should help. If you want to use windows software like EasyBCD, post your question on a windows forum. I used it in the past and it seemed to work but it's been years.

**alan44zz** · September 20th, 2024

> GRUB_DISABLE_OS_PROBER=false

Ok

grub-update : OK, windows entry has been added.

Yes ubuntu is on gpt disk.

Then I put the Ubuntu disk to boot first.

Reboot = Neither Grub nor windows, but error message saying Windows is corrupted ?!

That means that now I cannot even boot to Ubuntu at all...

I put back the Windows disk first. Reboot.

When I try to enter Ubuntu (EasyBCD choice...) I got this as told yesterday:

So it seems there's something to fix in the grub ...