I recently bought a Dell Inspiron 3521 (15”, Intel i3 processor, 4GB RAM, 500GB hard drive, A07 BIOS from InsydeH2O) with Windows 8 pre-installed. I expected to be able to install Ubuntu 12.04.2 from CD and dual-boot, as I do with my other main laptop (which has Windows 7). 95% of my work is done under Ubuntu, but I want to preserve access to Windows for a few things that require it.

This turned out to be MUCH harder than I expected. Forums provided conflicting and misleading info. No BIOS manual is available and Dell technical support didn’t officially want to help me as they said Ubuntu was unsupported (though some of the techss were nice to me and gave me some suggestions, unfortunately useless).

Questions: Can you boot from a CD under UEFI? Will the installation work if I boot Ubuntu in legacy mode? Should I have Secure Boot enabled or disabled? Why doesn’t the Ubuntu installer see the Windows system? If I repartition the drive manually, how should I do it? But mostly, what is the overall strategy for getting Ubuntu installed alongside Windows on this machine?

I’m an experienced user, but I don’t normally have to deal with technical boot issues or partitioning.

If I can’t figure it out, will it work to just trash the Windows installation and install Ubuntu on the whole drive?

Here is my Boot-Repair info:


1. Legacy mode or UEFI?

The BIOS offers the option to switch between Legacy mode and UEFI.

Booting from the Ubuntu CD in legacy mode is no problem. But if I do that and install Ubuntu, won’t it be a problem that Ubuntu was installed as legacy and Windows as UEFI?

I thought it was better to install Ubuntu from a CD booted under UEFI, and imagined I would be able to boot from the CD under UEFI by changing the BIOS settings to allow booting from CD. There is a tab in the UEFI section of the BIOS called “Add Boot Option” which on the face of it seems to offer a way to do this. If I select “Add Boot Option,” it asks for a name for the new boot option and then you can choose a file system and file path. But the only two file systems presented as options appear to be two partitions of the hard drive (they have very long names starting with Acpi). And there is no info anywhere on what to put in as the file path.

Interestingly, when I made recovery disks for the Windows system and tried to boot from them under UEFI, it recognized them, and then briefly presents the CD under the following file system name in the UEFI menu: Acpi(PNP0A03,0)/Pci(1FI2)/Sata(2,0,0)/CDROM(Entry 1).

2. If I use UEFI, should I have SecureBoot enabled?

Also, should have the Legacy OPROM on and what does that mean anyway? Should I have SecureBoot in Standard or Custom mode? Note that I already disabled fast startup in the Windows 8 settings.

3. Why doesn’t the Ubuntu installer see Windows 8?

When I boot the Ubuntu CD in legacy mode, and start the process of installing Ubuntu, it doesn’t see the Windows 8 OS. It just gives me two options: “Erase the disk and install Ubuntu” and “Do something else.” It doesn’t give me the “Install Ubuntu alongside other operating systems” option.

4. How can I edit the partition table to give Ubuntu space on the HD?

If I then click on “Do something else,” the partition table comes up with 6 partitions all of which are being used by Windows. Can I edit and rearrange the partitions to get Ubuntu to work? If so, how?


After much trial and error I figured out the reason for my problem. I was using an Ubuntu 12.04.2 image which had no EFI folder or other EFI boot information. (This despite the assurances everywhere that Ubuntu 12.04.2 is UEFI compatible. Admittedly, I downloaded the image from a mirror rather than from the official Ubuntu website).

Without an EFI folder, EFI boot managers (whether the built-in Dell one or rEFInd) do not recognize the Ubuntu image as bootable.

I downloaded another Ubuntu image and presto, it was recognized, and I was able to install it correctly. (Although I did have to shrink the Windows partitions and create partitions for Ubuntu manually.)


2 Answers 2


I think you might want to look at the entry on the ubuntu wiki about UEFI.


From the Ubuntu wiki

  1. if the other systems (Windows Vista/7/8, GNU/Linux...) of your computer are installed in EFI mode, then you must install Ubuntu in EFI mode too.

  2. if the other systems (Windows, GNU/Linux...) of your computer are installed in Legacy (not-EFI) mode, then you must install Ubuntu in Legacy mode too. Eg if your computer is old (<2010), is 32bits, or was sold with a pre-installed Windows XP.

  3. if Ubuntu is the only operating system on your computer, then it does not matter, you can install Ubuntu in EFI mode or not.

So if you keep Windows you must use EFI mode but if you trash it you can use any mode.


You have normally only used MBR until now which can only have 4 primary/secondary partitions. GPT can have as many as you like. However I don't know if you can swap them. You can resize them however I don't think that might cause trouble. I suggest you to use GParted for this (warning: fdisk does not support GPT) so choose Try Ubuntu. See the arch wiki for GPT infos. See also this.


Can you boot from a CD under UEFI?

Generally speaking, yes. As a practical matter, some EFIs make this difficult because of poor user interfaces. If you have trouble, try creating a USB installation medium; that might help. Another option might be to install my rEFInd boot manager using Windows. It should provide options to boot CDs or USB flash drives -- but there are cases when this doesn't work because of very flaky EFIs.

Will the installation work if I boot Ubuntu in legacy mode?

Generally speaking, keeping both OSes booting in the same mode (EFI/UEFI or BIOS/CSM/legacy) is the best policy. Some computers do permit switching between modes, but that's generally difficult. rEFInd can sometimes make this a bit less awkward, but you'll need to edit the refind.conf file, uncomment the scanfor line, and ensure that hdbios is included among the options. If successful, you'll then see a new grayscale icon that will launch GRUB (or whatever boot loader is installed in the protective MBR).

It's also possible to install Ubuntu in BIOS/CSM/legacy mode and then switch the Ubuntu boot mode by installing an EFI boot loader for Linux. This is usually more effort than installing in EFI mode to begin with, but if your firmware offers unusual obstacles to EFI-mode booting the Ubuntu installer, it might be your best option.

Should I have Secure Boot enabled or disabled?

In theory, Ubuntu supports Secure Boot. In practice, it often generates problem reports. Go ahead and try it with Secure Boot enabled, but if you run into troubles getting the Ubuntu installer (or installed Ubuntu OS on your hard disk) to start the boot process, disable Secure Boot. You can enable it later if you like. Note that if you see a GRUB menu or if the installer starts, Secure Boot is not a problem. If Secure Boot causes problems, the symptom is likely to be that the computer boots straight into Windows with either no error message or a brief message to the effect that a boot loader triggered a security violation.

Why doesn’t the Ubuntu installer see the Windows system?

From your description, Ubuntu did see Windows; it simply didn't present an option to automatically shrink the Windows partition and install Linux in the gap. You should do one of two things:

  • Before running the installer, shrink the Windows partition and leave an unpartitioned space for Ubuntu to consume.
  • In the installer, select the poorly-named "something else" option, shrink the Windows partition, and set up your Ubuntu partitions manually.

Personally, I prefer the second choice, since it will give you the opportunity to create a separate /home partition, which I consider important.

If I repartition the drive manually, how should I do it?

Ask 10 people this question and you'll get 11 answers. There are also about a bazillion Web pages on the subject. Do a Web search and take your pick of the answers.

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