Ubuntu and Kali Linux are two distributions designed for different groups of users – Ubuntu for general desktop use, Kali Linux for security professionals and more experienced users.

In this tutorial, you’ll learn how to install both Linux distributions and Windows 10 on a single hard disk drive and on a computer with UEFI firmware. That’s how to triple-boot Ubuntu 15.10, Kali Linux 2, and Windows 10 on a single hard disk drive and on a computer with UEFI firmware. To complete this tutorial, you’ll, of course, need to have either an existing installation of Windows 10 or be prepared to install a fresh copy of it. Whatever the case, this tutorial assumes that you have a computer with Windows 10 on it.

Kali Linux 2 and Ubuntu 15.10 will be installed in any order alongside Windows 10 on the same hard drive. The space for installing them will have to be recovered from the Windows 10 C drive, or another partition of the hard drive that has enough unused disk space. For this tutorial, Kali Linux 2 will be installed first, followed by Ubuntu 15.10.

How to install Kali Linux 2 has already been published, so if you want to follow the same scheme used in this tutorial, visit How to dual-boot Windows 10, Kali Linux 2 on a PC with UEFI firmware. After completing that part, come back here to complete this part of the tutorial.

To complete this part, you need to download an installation image of the desktop edition of Ubuntu 15.10 from http://www.ubuntu.com/download/desktop. Then burn it to a blank DVD or transfer it onto a USB stick. Afterwards, boot the computer with the installation media you made in place – either in the optical drive or in a USB port.

Because there are two versions of the installer, and to ensure that you boot into the UEFI-aware version, enter the computer’s boot menu before it boots into the installer. The reason is so that you manually select the entry that will boot into the correct version of the installer. The boot menu of the computer used for this tutorial is shown in Figure 1. You can see the entries for the boot managers of Kali Linux 2 and Windows 10. However, the entry we’re interested in, is the one that will boot into the correct version of the installer for this exercise. That entry is UEFI: SanDisk Cruzer Glide 1.26. So select the corresponding entry on your computer’s boot menu and press the ENTER key.

Computer Boot Menu

Figure 1: Boot options on the computer’s boot menu

You’ll then be prompted to either boot into the Ubuntu 15.10 Live desktop or to boot straight into the installer without making a pit stop at the Live desktop. Regardless of the route you choose to get to the installer, after it launches, click through the first two steps until you get to the one shown in Figure 2. The installer should correctly detect that there are multiple operating systems on the hard drive, so it gives you several options. By default it offers to install Ubuntu 15.10 on the free space, partitioning the space automatically.

Ubuntu 15.10 partition methods

Figure 2: Partition methods of Ubuntu 15.10

If you accepted the default option from the previous step, the installer will create just two partitions – the root and swap partitions. That’s fine in some cases, but it’s best to create a separate partition where your home folder will be located. That partition will be mounted at /home. So if you accepted the default option and are now looking at the window shown in Figure 3, click Go Back.

Ubuntu 15.10 default partitions

Figure 3: Ubuntu 15.10 default partitions

Then select the Something else option and click the Continue button, which will take you to the installer’s manual disk partitioning tool where you will be able to create all the partitions you need, including one that will be mounted at /home.

ubuntu 15.10 Something else option

Figure 4: Ubuntu 15.10 “Something else” option

Figure 5 shows that manual partitioning tool’s window. The first partitions listed belong to Windows 10. Take note of the one marked /dev/sda2. That’s the EFI Boot Partition where the boot files for Windows 10 and Kali Linux 2 are installed. The boot files of Ubuntu 15.10 will also be installed in that partition.

ubuntu 15.10 manual partitioning tool

Figure 5: Manual partitioning tool of Ubuntu 15.10

This just shows the lower part of the window that you saw in Figure 5. sda7, sda8, and sda9 are Kali Linux 2 partitions. Partitions that will be used to install Ubuntu 15.10 will be created from the free space. To start, select it, then click on the + button right under it.

Ubuntu 15.10 manual partitions

Figure 6: Kali Linux 2 and Windows 10 partitions on Ubuntu 15.10’s graphical installer

That should open the installer’s partition editor, where you only need to specify the size of the partition you want to create, and its mount point. Because there’s an existing swap partition on the hard drive, which was created during the installation of Kali Linux 2, we’re only going to create a root and home partition for Ubuntu 15.10.

buntu 15.10 partition editor

Figure 7: Ubuntu 15.10 partition editor

So let’s first create the root partition. The minimum recommended size for installing Ubuntu 15.10 is 6.9 GB, so any value higher that should do. If you intend to use the system for a long time, allocate more than twice that amount. In this example, I only allocated 10 GB to it. For the mount point, select / from the Mount point combo box. Click OK.

Ubuntu 15.10 root partition

Figure 8: Create root partition on Ubuntu 15.10

For the home partition, allocate all or as much disk space that you have to spare. The mount point should be /home. OK.

Ubuntu 15.10 home partition

Figure 9: Create home partition on Ubuntu 15.10

The two partitions you just created should be at the end of the list of partitions under the target disk. The final task here, is to click on the Device for boot loader installation combo box and select /dev/sda2 Windows Boot Manager. After that, click the Install Now button.

Triple-boot Ubuntu 15.10, Kali Linux 2 and Windows 10

Figure 10: Completed partitions for triple-booting Ubuntu 15.10, Kali Linux 2 and Windows 10

This is the installer telling you the partitions it’s about to format. Verify that it’s the same two you created plus the swap partition, then click Continue.

Ubuntu 15.10 format partitions

Figure 11: Formatting partitions for Ubuntu 15.10

After the installation has completed successfully, reboot the computer. By default, it should reboot into Ubuntu 15.10’s boot manager, which should show entries for Kali Linux 2 and Windows 10, besides an entry for Ubuntu 15.10. Reboot into each operating system to make sure that nothing has been messed up. If you followed this guide to the letter, you have a system with three operating systems installed on it.

Ubuntu 15.10 GRUB boot menu

Figure 12: Ubuntu 15.10 GRUB boot menu showing entries for Kali Linux 2, Ubuntu 15.10 and Windows 10