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I bought a Toshiba laptop with two partitions: C: with Windows 7 and D: with my data. I want Ubuntu 12.04 be installed in D: but when I try the computer shows me C: divided in two parts. If I choose Something else and select /dev/sda3 a message appears: There is not a root file system. What can I do?

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You have to search in the partition options. There should be an option that lets you configure the partition as Root System. – Lucio Jun 28 '12 at 17:17
up vote 2 down vote accepted

Follow the steps

  • Take backup every thing in D: drive. Because all data will be lost.
  • Boot with live usb
  • There will be screen asking for install options like install along with windows 7,install ubuntu as only OS etc. Choose Do something else option at the end.

  • Now partition tool will open. Delete the disk you want to install ubuntu to. You can see the unallocated space. Select that and then click on Add.

  • Now we will add SWAP partition. Give disk space value as 1024MB (1GB) or 2GB. If you have good amount of RAM (~2GB), 1GB swap space is enough. Select SWAP in file system dropdown.Press "OK".
  • Now again continue previous step for the rest free space (or whatever size you want for ubuntu installation). This time select filesytem as ext4 and mount point as /.
  • Check in partition tool window, grub installation location is same as your hard disk not your usb disk. (most likely bootloader location -> in sda ...)
  • Now go ahead and installation will finish in minutes.

Note: Don't enable downloading of 3rd party apps and update in previous screen. Better don't connect to internet while installing.Good luck. Let us know how it went.

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Thank you, now it's ok. – Alberto Ferrer Jun 28 '12 at 17:32

When you install Ubuntu you must define a root file system. This can be done by clicking on 'Edit Partiton' then you can define if and how the partiton is used. You can define how the partition is formatted and how the partition is mounted. At 'mount point' you must choose '/' to define this as the root partiton.

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The 'mount point' options I have are /dos /windows. Which one do I choose? – Alberto Ferrer Jun 28 '12 at 17:12

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