first of all, i'm really sorry for this question, i know there are tons of information on the web covering this, but i really need to get this right this time, as it's the 3rd time i installed windows and ubuntu and now i don't want to go through this again... Here's:

the rundown of my last failed install:

  • within windows 7 installer
    - Cleaned my new 500GB Disk
    - Created a partition for Windows 150 GB
    - Created a partition for Linux - 100 GB
    - Created a partition where i hope to install OSX in the future(100GB)
    - Created a partition with the rest (around 140GB) where i hope i will keep everything i want to share between OSs
  • Installed Windows (that created that 100Mb system partition)
  • Installed Linux
    - only had two options: replace windows or advanced
    - i chose advanced - only the 150GB windows partition showed allocated, all the rest was "free"
    - created a swap partition of 2GB for swap - created a root partition of 100GB, and installed linux there

The result was disastrous:

  • Linux was fine, but
  • I got blue screen when booting Windows
  • Windows installation didn't recognize my Hard Drive any more
  • I had to run linux installation again, reformat the harddrive, cancel the installation so windows would recognize it again...

So, now:

  • I deleted the linux partitions in windows installation
  • Createa a partition of 150GB for windows
  • Installed Windows
  • Installed Linux, with the previously unavailable option (alongside windows)
  • Everything went well, i have both systems running

What i need
I want the same partitioning setup, i described in the beginning:
- a partition for Windows 150 GB
- a partition for Linux - 100 GB
- a partition where i hope to install OSX in the future(100GB)
- a partition with the rest (around 140GB) where i hope i will keep everything i want to share between OSs

I just need to know, exactly what i need to do and how to do it, in a way that nothing goes wrong, and i don't have to go back to square 1.

Thanks for your time, much appreciated

4 Answers 4


A warning first: Windows does not like it if you mess with its partitions, particularly from outside Windows itself. The safest way to do it is as you've already done, so I think you're in good shape to go further. However, a bit more information will help: Is Windows on the first partition? If so, leave it there! Do not even think about moving or resizing the Windows partition!

That is, if I understand correctly what you did. You installed Linux next to Windows, right? So you now have two partitions, right?

If Windows is in the first partition, the rest is pretty easy. Using GParted you can create all the remaining partitions. Is Linux already in a 100 GB partition? If not, boot from the Linux live CD (or DVD) and choose to try it, not install it. When you get to the desktop, you can run GParted and resize the Linux partition as you need; do not touch the Windows partition! If it isn't already there, go ahead and add the Linux swap partition, too. You can then divide the empty part of the drive as you'd like; if you want to have a partition available to all the OSes, you should probably format that partition with NTFS (to make Windows happy with it), and leave the partition destined for a future installation of OSX unformatted for now.

Remember, do it all from a Live CD or DVD, and don't mess with the Windows partition at all. If you do move the Linux partition, you'll probably need to reinstall Grub, but that's easy and instructions are easy to find here in AskUbuntu.com, but it would also be a good idea to boot back into Linux (not from the Live CD or DVD) and use the instructions here to get and install Boot Repair, which can also reinstall Grub if needed.

  • this worked perfectly. thank you very much Commented Mar 4, 2012 at 18:05

You need to understand all of the following well:

  • Partitions - primary vs logical, file systems, what each OS requires.
  • Boot loaders - what they are, how to install/fix them, and what they can/can't boot.
  • MBR - just what it is. It comes up a lot when dealing with boot loaders.

How to do it: practice, ...a lot.

Apologies, if that's not what you wanted to hear. The only other way I can think of is paying someone to do it for you.


I'm not exactly sure what your current situation is. Is the linux partition 100GB or taking the rest of the disk? Where is the MBR located and are you using grub/lilo to boot?

Normally, if you think out how many space you need beforehand and for what (as you did) there shouldnt be a problem. Write down everything on paper. Boot a livecd first if you need to.

Install GParted on ubuntu. It gives you a visual overview of all the different partitions and OSes you have. Editing is easy with a simple list of what is going to change before pressing OK. Ofcourse you should backup important data before resizing, but I never did and it always worked out fine.. (but that is not really an argument :>)

After that you might need to fix your bootloader. Since Ubuntu now uses grub 2 configuration has become a bit different. Ofcourse there is a nice and easy tool for this as well. Install grub-customizer to add everything the os prober cant find.


Here are the steps I'd take:

  • Run the Ubuntu installer.
    • Create a new MS-DOS partition table on /dev/sda
    • Create a primary partition for Windows and leave it unformatted
    • Create a primary partition for OS X and leave it unformatted
    • Create a logical partition for Ubuntu and format it to EXT4
    • Create a logical partition for shared files and format it to FAT32
    • Create a logical swap partition
    • mount the EXT4 partition as / and finish the installer, writing Grub to /dev/sda
  • Run the Windows installer
    • select the unformatted Windows partition, format it to NTFS, and select it, then finish the installer
  • Run the Ubuntu Live CD
    • Run "grub-install /dev/sda && update-grub"
  • Reboot and make sure that both OSes work. If you've correctly followed these steps, they should.

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