In previous articles I shared two methods in order to install the new version of Ubuntu 20.04 LTS on our computer, this taking into account in one case if we want to make the jump to this new version from a previous one or if we want install the system on our computer from scratch, being this the only one in the team.
For another type of case and that is usually quite common, is when you want to have two systems installed on the same computer, that is, a dual boot. Which in most cases is usually Windows with Ubuntu.
In this stage, I must take into account that you already have Windows installed and you want to have Ubuntu on the same computer, regardless if they are on two different disks, this does not matter.
But I must clarify that If you plan to install both from scratch, I recommend that you always install Windows first. before Ubuntu. And this is because if you do it the other way around, Windows takes full control of your system startup and will only start it, completely ruling out Ubuntu.
Although all is not lost, since can you recover Ubuntu boot with a fairly simple tool from Windows or rebuilding grub from live mode from Ubuntu, but these are really avoidable steps if you do things right.
Installation Process
Well, the first step to install alongside Windows is download the ISO de Ubuntu LTS 20.04 and burn it to removable media, be it a USB, SD or DVD.
In this case, the most common is a USB and for this we are going to rely on an excellent tool called Rufus, which you can download from this link.
We open Rufus and we are going to select our USB, select the image to record and set the mode in BIOS / UEFI, the rest we leave as is and click on start.
It will throw us warnings that the content of the device will be deleted and other things. Then a window will appear asking us to confirm the recording method, in which we choose DD. We start and we only have to wait for the process to finish to restart our computer, but before doing so let's open a console (command prompt) in Windows con admin permissions to disable fast startup as this can cause some problems with the installer.
In it we only type:
powercfg /h off
And with that we can continue, but in case you start Windows again before installing Ubuntu, you will have to re-execute the previous command.
Note.
If you are going to install Ubuntu on the same disk where Windows is installed, it is important that you assign a partition "at least" for Ubuntu, this can be done from Windows with the disk management tool or from Ubuntu with the help of the installer, this is already at your choice.
removable media boot
Now it's time to boot the removable media, here it is important that you modify the boot options of your bios and in case it has UEFI enabled, you deactivate it. Here in this step I apologize, but I cannot cover this section, since due to the large number of boards and bios that exist, the configurations differ in some things, but you can find information about your board or bios on the web.
Once the removable media has started, we will be inside the installer and yeswe will follow the steps requested by the installer (nothing to write home about), the process is similar to the guide I shared earlier. (you can check in the following link)
The only difference is that when choosing where to install Ubuntu we are going to "More options" and we will be shown a new window that displays the information of our diskHard (s) together with the systems we have installed. Here as mentioned above you can modify this part to assign a partition to Ubuntu or to have already done it from Windows.
In this option we can see something like this, where in my case I have a previous version of Ubuntu next to Windows on a disk and in another that I have dedicated only to Arch Linux. To select the disk where Ubuntu will be installed we can do it in this window.
In my case only I am going to delete the one from Ubuntu 18.04 and I will occupy that same space for the new version.
In the settings, we occupy all the space of that partition, we format in ext4 and in mount point «/» or in case you have assigned more partitions or space you will assign the mounting points of each one.
Finally if it is only a single partition, you will not move the place where the grub will be installed, in case of being on another disk you will indicate that the grub is installed on the disk where you are going to install Ubuntu and in this way you do not damage the Windows boot and in Ubuntu the option to boot from Windows is added.
We install now and continue with the process.