Is it easier to install Ubuntu on a Windows 10 machine or Windows 10 on a laptop running Ubuntu

Solution 1:

Dell laptops that come with Ubuntu preinstalled have a selection of hardware selected for optimal compatibility with Ubuntu that is different from the same model Dell laptops that come with Windows preinstalled. In addition to this, the default UEFI settings of Dell laptops that come with Windows preinstalled are optimized to run Windows well. So in addition to considering which operating system to install first, you also need to consider which operating system will be used the most, Windows or Ubuntu.

In the pure case of which operating system to install first, it is preferable to install Windows first because if you install Ubuntu first then the Windows installer will replace Ubuntu's GRUB bootloader with the Windows bootloader, and you will have to use Boot-Repair ( bootrepair ) to repair the GRUB bootloader after installing Windows, so that both Windows and Ubuntu will boot.

Solution 2:

The Windows installer (more importantly the automated creation of the boot manager/BCD data) doesn't have the ability to identify other installed OSes (such as Ubuntu) and therefore give you the choice upon boot.

In contrast, however, the Linux installer (again, more importantly the GRUB2 installer) DOES have the ability to identify that other OSes exist on the same hard disk; and it knows to create the correct boot data to allow you to choose which OS to boot when your computer boots.

It's important to understand that when you install GRUB (GRUB2 for modern releases of Linux) that it becomes the initial bootloader for your computer. The Windows boot manager will exist but GRUB knows to hand off to it to boot Windows - this is known chainloading.

The Windows boot manager can be used to boot Linux, but it is much more complicated as you need to edit the BCD data manually to add the entry.

Using GRUB2 automates the boot data hard work for the user.

As a result, it is easier (and recommended) to install Linux after Windows -> the installer will identify Windows and ask if you want them to run side-by-side -> you decide what you want! (The Windows installer isn't this nice to other OSes! It'll see the partitions but not the OSes so won't allow you to choose - it'll become the default).