Currently my computer runs on Windows 7. Now I want to install Windows 10, but do a clean installation (no upgrade). After that, I want to install Ubuntu alongside Windows.

I'm wondering about the best way to partition my hard drive. Should I

  • Create an extra partition for Ubuntu directly as I install Windows 10 (in its installation menu/process).
  • Create an partition for Ubuntu as I install Ubuntu (via the "Something Else" option in its installation menu/process).
  • Just install Ubuntu alongside Windows and the installer creates a new partition for Ubuntu automatically (I'm not sure if this is how it usually works, which is why I'm asking).
  • 3
    UEFI or BIOS? Most Windows 7 systems are BIOS and then have MBR partitioning with the 4 primary partition limit. You cannot in Windows create partitions for Linux, it does not know Linux file types. And if you try to create more than the 4 partitions in Windows it converts to dynamic partitions which are Windows proprietary and do not work with Linux. I prefer to manually partition, but if you just want default / (root) and swap then auto install works. Best to use Windows to shrink NTFS partition and reboot immediately so it can run chkdks. And with Windows 10 make sure fast start if off. – oldfred Mar 28 '16 at 14:33
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    It's important to do one thing before a clean install: check if you still have your Windows 7 key. If you lost it, it's not a good idea to install Windows 10 from scratch right away, since you'll have no product key for it. Instead, you'll need to upgrade to Windows 10 instead of doing a clean install, check that Windows 10 is not just installed and running but that it's also activated (causing Microsoft to remember your computer for later Windows 10 installs), and then do the clean install from there. – Olathe Mar 29 '16 at 1:08
  • Instead, you'll need to upgrade to Windows 10 instead of doing a clean install Actually, that is not needed anymore with the latest version of Windows 10 (which you can download from Microsoft) ! In the latest version you can just install using your Windows 7 key OR install without providing a key but activating Windows 10 after installation with your Windows 7 key. So make sure you have your windows 7 key (it might be printed on a sticker on the PC, if not use the Magic Jelly Bean keyfinder tool). – Bimpelrekkie Mar 29 '16 at 9:22
  • Make sure you get the download for the iso usb that has november release already included! Also, best to have legacy if you want a dual boot. If your do uefi, give yourself 500 mb. Mine is already using 350 mb. And I am legacy...figure that one out? Uefi is what gives trouble for dual boot booters. Unless you are worried about security, I would forgo it. I did a clean install/format in legacy last week and I am loving it. – Bhikkhu Subhuti Mar 29 '16 at 11:58

It is generally not recommended to work on disks and partitions from within a running operating system. So prepare the disk before installing any system to avoid possible trouble later on. Boot from the Ubuntu installation media you created before and select Try Ubuntu without installing.

Open GParted, create a new partition table. This will erase the disk, so backup your data before.
In case you have an UEFI based BIOS, select gpt. In case you have a legacy BIOS, select msdos. Now create new partitions for Windows - here you find all information about what to consider :

After having prepared the partitions for Windows, prepare the partitions for Ubuntu. Creating an EFI partition is not necessary, because this already has been done before. All boot loaders will be installed there, the Windows boot loader and the Ubuntu GRUB boot loader.

Create a new partition - format it with ext4 - choose a size of minimum 20 GB.
Create a new partition - format it with swap - choose a size matching the RAM.

First install Windows, disable hibernation and fast startup, then shutdown the PC completely.

Now install Ubuntu, boot from the install media - select Try Ubuntu without installing. On the desktop click Install Ubuntu - when asked what to do - choose Something else. Select the ext4 partition you had created with GParted for the Ubuntu system before. Select / as mount point and ext4 file system as format and then start the installation of the Ubuntu operating system.

Here you find further information including a GParted presentation : How to prepare a disk ...

  • Gpt is not allowed for windows 10 install. I know this from experience and had to scramble just after I told windows to format before installing. – Bhikkhu Subhuti Mar 29 '16 at 11:54
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    @BhikkhuSubhuti : GPT is the default partition table on modern hardware and mandantory for installation of Windows 10 in EFI mode. When you have a legacy BIOS based computer - you have to install Windows in legacy (MBR) mode of course. :) – cl-netbox Mar 29 '16 at 12:14
  • I was wondering why my 32gb sdd was formated with gpt! It seemed overkill once i learned the difference between the two. I wonder if you can switch to efi once already installed..like I care, but in any case...my comment was related to legacy install (last week). In any case, i think Ubuntu will recommned legacy for dual boots. Certainly the linux kernel person bugnfixer assigned to me said so. – Bhikkhu Subhuti Mar 29 '16 at 12:48
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    @BhikkhuSubhuti : There often is some confusion about this topic ... important is that all systems have to be installed in the same mode, so on an UEFI BIOS based machine with GPT partition table disks, Ubuntu and Windows have to be installed in EFI mode and on legacy BIOS based machines with msdos partition table disks, Ubuntu and Windows have to be installed in legacy BIOS (MBR) mode. :) – cl-netbox Mar 29 '16 at 12:59
  • You can change the bios to boot in legacy mode. I have a brand new machine with uefi. I turned it off and I am loving it. – Bhikkhu Subhuti Mar 30 '16 at 23:35

It is always better to install Windows before Ubuntu. First perform a clean install of windows 10 then proceed with ubuntu installation. I would highly recommend you to create a partition within windows itself using the disk management utility before proceeding if you know what you are doing. You could directly select install ubuntu alongside windows option but at times I have seen windows not booting after installation. Morever I think it is the safest option to create a partition inside windows, then boot from ubuntu live-disc and select something else option and creating the root and swap partition from the partition already created and proceed with installation.If you are doing a fresh install create an extra partition for Ubuntu directly as you install Windows 10 and then boot from liveusb. Remember to switch off fastboot in WWindows 10.It sometimes causes problems.

  • 1
    I STRONGLY recommend against creating Ubuntu partitions within Windows. This is especially important when using MBR (as on a BIOS/CSM/legacy install), since the Windows partitioning tools are very likely to switch to an LDM setup, which Ubuntu can't use. Windows is less likely to create something unusable when the disk uses GPT, but even then, Ubuntu will need to adjust the partitions' filesystems, at a minimum, so you might as well leave a big unpartitioned space and then create partitions with the Ubuntu installer. – Rod Smith Mar 29 '16 at 23:53

Firstly, find out which partition table you use.

You can do it for example from live usb in terminal by typing : sudo parted --list or in Windows http://thpc.info/how/gpt_or_mbr.html .

If it is GPT, which is probable if you use newer machine, just install Windows 10 and then create in Windows disk management unallocated space where Ubuntu will be installed.

And after that when you will install Ubuntu, if you choose the option Install Ubuntu alongside Windows, Ubuntu will create automatically its boot partiton and swap partiton in this unallocated space without affecting anything else or you can always do it manually by Something else option.

I did it like this and I chose Install Ubuntu alongside Windows option when I installed Ubuntu 14.04.4 LTS alongside Windows 7 and everything went flawlessly.


It is always better to have a live-CD or a live-USB of an utility called GParted. I wouldn't recommend partitioning from alerady installed operating systems, because this could lead to data loss or to other strange errors. So you should first install one of the OS'es, then create a live-CD or a live-USB of GParted(using the following manual), partition the drive and install the second OS. I have done this many times before and it worked flawlessly. So try thi

  • Or you can use an Ubuntu live disc and launch GParted from there. But then I've never used a GParted live disc, so I don't know if there are any differences. – wjandrea Mar 28 '16 at 21:09
  • It helps, when you want to install Windows first – TimurEke Mar 29 '16 at 6:54

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