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I have a disk with 3 partitions:

  • 100MB for Windows 7
  • 97.56GB for Windows 7
  • 125.91 which I want to install Ubuntu on

How can I install Ubuntu on the 125.91 GB partition "alongside" Windows 7 (including grub etc) so I can dual boot between the two? Usually I get the "alongside" option available.

If I select "something else", click on the 125.91GB partition and then "install now" it says

"No root file system defined".

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up vote 2 down vote accepted
  • After selecting something else , you would be presented with the window which contains all your partition.
  • Select the partition on which you want to install ubuntu (in your case it is 125.91 GB partition ).
  • Now click on edit partition, It will present a popup window . Select "partition type" as ext4 journaling file system, check the "format partition" option and select "mount point" as /. Now click ok.
  • It will ready the partition for ubuntu installation. Now click on proceed button to proceed the installation process.
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Top man- exactly what I needed. Simple instructions! – user997112 Feb 25 '14 at 20:16
Ok I have edited my answer. – g_p Feb 25 '14 at 20:32

Try to install Windows first, then install Ubuntu. The problem is that Widows will not prepare for you boot manager for two OS's alongside. Ubuntu is needed to be installed at the end.

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