A few weeks ago I bought an Acer Aspire E1 522 Notebook with an AMD A6 quad-core processor. I wanted to install a dual boot with Ubuntu, but the Ubuntu installer did not give me the option to "Install alongside Windows". I continued the installation and I lost Windows 8 (a little evil). Then I decided I wanted to start over and do a dual boot with Windows 7. When I rebooted the computer to start Windows 7, the computer gave me an error saying that the security settings did not allow to start the disk.

So I entered the UEFI firmware and I removed the safety lock; however, the computer would not let me install Windows 7. So I changed the BIOS mode in Legacy (I was right) and I finally installed Windows. Then I restarted the computer to install Ubuntu 14.04.1 with the exact same problem starting (I did not check for the next Windows install). Finally I opened the GParted live which gave me an error message saying that probably the GPT partition was erased or corrupted.

What should I do? I only would like to be able to install and use these two operating systems, nothing else. Thank you!


When the installer asks whether you’d like to Install Ubuntu alongside another operating system, OR delete your existing operating system and replace it with Ubuntu, choose the Something else option.

Create partitions using the Ubuntu Installer

Dual Boot Partioning Guide

In general, a Windows 'should' be installed first, because it tends to ignore other operating systems and does not include them in it's boot-menu. Also Windows installers tend to overwrite the entire hard-drive (potentially wiping out any other data stored on it).

Here's my dual boot setup. Though I've never had a reason to install Windows.

Ubuntu Windows dual boot

  • Be careful what you're doing in the partitioner if you select the Something else option, so that you don't accidentally delete your Windows partition. – karel Jul 27 '14 at 17:09
  • It seems to me that he already lost it. – Gayan Weerakutti Jul 27 '14 at 17:22
  • It doesn't matter because when you are creating a dual boot setup, you should install Windows first before Ubuntu. That's because the Grub bootloader will also have the existing Windows boot information, but Windows overwrites the boot information of an existing Ubuntu OS during its installation. – karel Jul 27 '14 at 17:26

You've made one change after another, each of which fixed one problem and created a new one. At the moment, you've probably got a BIOS/CSM/legacy-mode installation of Windows on an MBR disk, but with leftover GPT data because the Windows partitioning software does not completely erase GPT data when doing a GPT-to-MBR conversion. This setup confuses libparted (upon which the Ubuntu installer's partitioner is based), leading to the symptom you're seeing. The solution is to erase the leftover GPT data. The easiest and safest way to do this is to use FixParts, which is included in the Ubuntu gdisk package. (There's also a Windows version available, in case you want to run it from there.) In brief, when you run the program, it will note the presence of leftover GPT data and ask if you want to remove it. Respond in the affirmative and then exit.

Note that once this is done, you must boot the Ubuntu installer in BIOS/CSM/legacy mode, rather than in the EFI/UEFI mode you probably used before. Typically, if you can get to the firmware's built-in boot manager, you should select the option to boot your medium that lacks the string "EFI" or "UEFI." If you accidentally boot in EFI mode, the Ubuntu installer may refuse to install, may overwrite Windows again, or may install in EFI mode on your MBR disk. (I don't know offhand what it actually does; but none of those three options will be helpful to you.)

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