If you discover that Windows 8 isn't quite your cup of tea, and you have no feasible path to downgrade, it may be a good idea to dual boot with Linux to have an alternative operating system you can use. For most people, using Ubuntu is an excellent choice because of its popularity, software selection, hardware support, and ease of use. However, if you want to dual-boot, you need to do a few things before you’re ready to enjoy your Linux installation.

A few side notes: as the title of this article may imply, this article is about installing Ubuntu after Windows 8 is already on your computer. Installing any version of Windows after installing Ubuntu will require a different process that will not be covered here. Additionally, these instructions can be applied to any other Ubuntu-based distribution without any modifications.

Non Ubuntu-based distributions can also be installed this way with some minor modifications to the instructions. For those distributions, it’s best to check the project’s documentation for official guidance, but a similar process should be used.

Download & Burn Ubuntu

If you haven’t already, go ahead and download yourself a copy of the latest Ubuntu version (13.04 at the time of this writing), and don’t forget to make sure that you’re getting the 64-bit version instead of the 32-bit version as it comes with EFI support if you need it. Once it’s downloaded, burn the ISO file onto a DVD or USB flash drive.

There are now two different ways for you to install Ubuntu -- a simple, automated manner that takes care of everything for you, or a manual process that gives you more control.

Simple Way

dual boot windows and ubuntu

Boot your computer with the new Ubuntu media. The installer has come so far now that there’s very little that you actually have to do by yourself. Once the media finishes loading, it’ll ask you whether you’d like to try or install Ubuntu. Choose your language from the left and click on Install. You should now be able to choose “Install Ubuntu alongside them” which will make all the necessary changes on your computer to make room for Ubuntu and install it properly on your system, no matter if it will install operating systems in the legacy BIOS mode or the new EFI mode.

Before the installer commits changes to the disk, it’ll ask you how you’d like to split your hard drive between the two operating systems, so make that decision as you please and carry on with the installation.

Manual Way

First things first, you’ll need to make space on your hard drive for the Ubuntu installation. While your hard drive may be showing free space within your Windows partition, you’ll actually need to shrink the partition itself in order to produce the necessary space to create a partition for Ubuntu.

There are two ways you can do this -- by using Windows’ Disk Management Tools (which you can find by right clicking on “Computer” in the Start Menu, and choosing Manage, then looking in the left-side pane), or by using a partitioning tool such as GParted within Ubuntu’s Live environment.

dual boot windows 8 and ubuntu

You’ll generally find two or three partitions already on your hard drive - these are all related to your Windows installation. Simply shrink down the largest of these partitions by however much space you want to give your Ubuntu installation. You’re shrinking this partition because the other two are related to Windows’ boot process and should not be altered in any way. After you've shrunk the partition, you do not need to create new partitions for your Linux installation as you’ll make the necessary partitions in the Ubuntu installer.

Boot your computer from the Ubuntu media and choose to install the operating system. Please note whether you saw a purple screen with a small keyboard icon at the bottom center or a black and white selection menu while the media loads, as this is important later. When asked about how to allocate space, choose to do “Something else”. This will open a partition editor screen where you can create your partitions. You’ll need to create 1-2 partitions here, depending on your system and your own preferences.

BIOS Boot

dual boot windows 8 and ubuntu

If you saw the purple screen while the media was loading, then your system used legacy BIOS to boot the media. Within the allocated space, you can create a Linux partition (preferably ext4) and set its mount point to root (“/”). If you wish to have a swap partition (which acts as a place for data stored in RAM to go for hibernation or as an overflow container), you can leave enough space to create one. The good rule is for the swap partition to be twice as large as the installed amount of RAM.

Also don’t forget that if you’ll end up having more than four partitions, you’ll first need to make an extended partition that spans across all of the unallocated space on your hard drive before creating the Linux and swap partitions within the extended partition. Once you've done this, continue with the rest of the installation. Ubuntu will install GRUB to your MBR, which can allow you to choose between Ubuntu and Windows during each boot.

EFI Boot

dual boot windows 8 and ubuntu

If you saw a black and white selection screen, then your system used EFI to boot the media. Choose to do “Something else” when asked about how to allocate space. You’ll probably want to reuse Windows’ EFI partition as EFI partitions need to be at the beginning of the hard drive, and using it for Ubuntu as well will not destroy the contents needed to boot Windows. The EFI partition should be formatted as FAT32, and typically with only 100MB.

You may increase this size to 200MB if you wish to go through the struggle of having to move the other partitions out of the way first to make the room. Then choose the EFI partition, and make its mount point be

        /boot/efi
    

if it’s not already.

dual boot windows and ubuntu

Then continue to create your Linux partition(s) (and swap partition if desired), and finish with the installation. An EFI version of GRUB will be installed which will allow you to choose between Windows and Ubuntu during each boot.

Troubleshooting and Conclusion

These tips should help you be able to dual boot Windows 8 and Ubuntu. The chance of any issues occurring is very low, but feel free to comment on the article with any questions that you may have. The only concern is if you get a “Secure Boot” or “signature” error when you try to boot the Ubuntu installation media. If that happens, you will have to go into your system’s BIOS and disable the Secure Boot option. For other troubleshooting, check out this article on installing Linux on a Windows 8 PC.

If you're new to Ubuntu, check out our great Ubuntu guide for beginners!

Do you dual boot Windows and Ubuntu? What’s your stance on EFI vs. BIOS? Let us know in the comments!

Image Credit: Ubuntu Wiki