Alternate titles: How to dual-boot Ubuntu 12.10 Desktop and Windows 8 Pro; how to dual-boot Windows 8 and Ubuntu 12.10; dual-booting Windows 8 and Ubuntu on a single hard drive (HDD).

So, I got a friend to lend me his copy of Windows 8 Pro. Armed with it, and an installation image of Ubuntu 12.10 Desktop, I set out to see if dual-booting the latest offerings from Microsoft and Mark Shuttleworth’s outfit will pose any major obstacles on a motherboard with UEFI firmware. The computer I used is one I assembled using an ASRock motherboard.

I started by using a 128 GB SSD, but all attempts failed. I couldn’t pinpoint what the issue was, so I abandoned the SSD and switched to a regular hard drive – a 500 GB HDD. (You read my experience with the SSD at why is Windows 8 on SSD invisible to Ubuntu 12.10′s installer?.)

What follows is a step-by-step guide on how I succeeded in dual-booting Windows 8 Pro and Ubuntu 12.10 Desktop on a computer with UEFI firmware on the motherboard, using 64-bit installation images of both operating systems. The objective: Set up the system so that GRUB, Ubuntu’s boot loader, is installed in a boot partition, making Windows 8’s boot manager the primary boot manager. So that on each reboot, you will see Windows 8’s boot menu as shown in the screen shot below.
Windows 8 Boot Menu

I made two installations. The first was on real hardware using 64-bit installation images of both operating systems. The second was in a virtual environment using 32-bit versions of both. Either attempt worked the first time. Not a single hitch.

Note that this article does not address dual-booting between Windows 8 and Ubuntu 12.10 on a computer preloaded with Windows 8. Such computers tend to have additional partitions for Windows that you will not create on your own. Not to mention the problem associated with Restricted Boot (Secure Boot).

So, here are the series of steps that I took to get this to work:

A. Download Ubuntu: Installation images of Ubuntu 12.10 are available from here. A 32- or 64-bit image worked, so download what you like or what will work on your computer.

B. Install Windows 8: This assumes that you have an installation DVD of Windows 8. When creating the partitions for Windows 8, set aside some free space for Ubuntu.

C. Install Ubuntu: Ubuntu was installed in the free space created when Windows 8 was being installed. Like the Windows 8 installation, this requires manual disk partitioning, so if you are not familiar with disk partitioning in Linux, be sure to read guide to disks and disk partitions in Linux before starting. Also, read Ubuntu 12.10 installation and disk partitioning guide.

D. Add Entry for Ubuntu in Windows 8: If you boot into Windows 8 after installing Ubuntu, you will have to add an entry for Ubuntu in Windows 8’s boot menu.

Once those four steps are completed, you should have a computer with Windows 8 and Ubuntu 12.10 installed on a single hard drive in dual-boot fashion.

1. Windows 8 Installer: So, let’s get started. Reboot or boot the computer with the Windows 8 installation DVD in the optical drive. Once the installer starts, click through until you get to the step shown in the image below. Note that this image and the two below it were taken from the test installation in a virtual environment, so the disk size will be different from what you’ll see in the Ubuntu installation images further down. Those were taken from the test installation on real hardware, which has a 500 GB HDD.

To create partitions for Windows 8, click on the New link.
Windows 8 Partition Tool

1a. Specify Disk Size for Windows 8: Specify the amount of disk space you want to use, then click Apply. For this tutorial, I specified 75,000 MB, or 75 GB.
Windows 8 New Partition

1b. Windows 8 Partitions: From the disk space you specified, the installer will automatically create two partitions for Windows. For all the test installations I’ve done so far, the System Reserved partition always got 350 MB of disk space. After installation, I observed that of that amount, more than 200 MB was used initially (about 242 MB on the 64-bit version, and about 210 MB on the 32-bit version). Click Next to continue with the rest of the installation. Note that Drive 0 Unallocated Space is what will be used for Ubuntu.
Windows 8 Create Partition

(Note: Aside from some eye-candy and intrusive configuration options, there is really no major difference between Windows 8’s installer and that of Windows 7.)

After Windows 8 has installed successfully, reboot the computer, with the Ubuntu 12.10 installation DVD in the optical drive. You can start Ubuntu’s installation process from the live desktop or without booting into the live desktop. Whichever option you choose, click through until you get to the step shown in the image in Step 2 below.

2. Ubuntu Installation Requirements: This just informs you what you need to install Ubuntu 12.10. A fresh installation of Ubuntu 12.10 actually takes less than 4.9 GB of disk space. Compare that to almost 15 GB for a new installation of Windows 8. Continue.
Install Specs

3. Ubuntu Disk Partitioning Methods: This step gives the options for partitioning the disk. The default, Install Ubuntu alongside Windows 8, will overwrite Windows 8’s boot loader in the Master Boot Record (MBR), which is not what we want. While it also sets up a dual-boot system, it has disadvantages that you do not want to deal with. And you definitely don’t want to choose Replace Windows 8 with Ubuntu. The option you want, is the last one – Something else. Selecting that and clicking Continue will take you to the Advanced Partitioning Tool.
Install Specs