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When I run the setup for 14.04 using the live USB and select "something else" for manually creating partitions on my hard disk, for some reason Ubuntu isn't able to detect other partitions and assumes the entire HDD is unallocated. This is explained in the snapshot below:

enter image description here

The description of the actual partitions are as under:

C:    NTFS   90GB   (running Windows 7)
D:    NTFS   80GB
G:    NTFS   80GB
H:    NTFS   130GB
Free space: 85.66GB

Ubuntu is unable to identify these partitions.

I have been dual booting Ubuntu and Windows for a while now and installed different versions of Ubuntu over Windows at least a dozen times, but never faced this issue. Until recently, I was running 13.10 and upgraded to Trust Tahr. That's when the problems began. The upgrade was successful, but once I rebooted I wasn't able to log into Ubuntu (probably due to a change in the boot loader from Legacy to UEFI, which I am certain grub was supposed to handle, but whatever!). One thing led to another and a re-installation attempt led to me having a single OS on my laptop(Tahr) and me losing all data. I removed Tahr, re-installed Windows 7 Home Premium and created the partitions. But now, I am unable to get Ubuntu to identify the partitions and the right amount of free space.

Given below are snapshots that show the error message I get when GParted tries to detect my partitions. I am certain something is wrong with my partition table, but I do not know what it is or what the message really means. But this might be why Ubuntu is unable to detect my partitions.

GParted error dialog box

GParted unable to find partitions

Windows 7 (Home Premium) Disk Management Tool Snapshot:

enter image description here

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You can boot Ubuntu Installation in UEFI mode. –  Sweetlove Sunny Apr 21 at 18:53
    
It's not about booting Ubuntu in UEFI. I am doing that, but I have to install it first in the right partition (I have kept aside 85.66GB worth of space for it). Problem is it is unable to detect existing partitions and if I proceed with the installation, it will simply wipe my whole disk and just install Ubuntu on my 500GB HDD. –  Darth Coder Apr 21 at 18:56
    
Hi I m having same problem Window 7 already Installed and tryinh to install Ubuntu but ubuntu not able to recongnise Window 7 partition and free sapace it is showing me as single harddisk, amazing thing is when I have run fdisk/ gdisk both showing me window partion but OS Installer does'nt see any partition. please suggest. –  Shalin Singh Jul 6 at 6:05

6 Answers 6

up vote 4 down vote accepted
+25

You have two issues. Windows only boots in BIOS mode from MBR(msdos) partitioned drives. It looks like drive was originally gpt. And when you install Windows in BIOS boot mode it does not correctly convert to MBR, but leaves a backup gpt partition table. Windows only boots from gpt drives with UEFI, so if you want to convert to gpt partitioning, you have to reinstall Windows in UEFI boot mode, if your hardware is also UEFI capable.

You can remove backup gpt partition table with fixparts. The Linux will see it as MBR without issue. FixParts is the easiest way to remove the stray GPT data. GPT fdisk (gdisk or sgdisk) can do it, but the procedure's a bit more involved.

http://www.rodsbooks.com/fixparts/

But it also looks like you have used all 4 primary partitions. You have to convert one primary to an extended partition, so you can create as many logical partitions as you want inside the extended. Do not create partitions with Windows as it will convert to dynamic partitions which does not work with Linux at all.

My laptop already has 4 primary partitions: how can I install Ubuntu?

My laptop already has 4 primary partitions, how can I install Ubuntu?

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Thanks for the information! I did not know this about the GPT tables and the UEFI boot mode, which my laptop actually does support. Just to point out: I have set aside around 80GB worth of free space for my linux installation. In fact, I have done this before and never faced any issues installing Ubuntu. Should I leave the free space as free or convert it into a logical drive which Ubuntu can use? Also, if I use FixParts, is there any chance of losing data? –  Darth Coder Apr 27 at 21:37
    
If drive was converted to MBR, then using fixparts to remove backup gpt partition table should not matter. You can directly install Ubuntu into the free space. If you want default of / (root) and swap that is the best way to install. But if you want other partitions then better to use gparted to create partitions and use Something Else to install. –  oldfred Apr 27 at 22:08
    
See the problem is, given the current situation, Ubuntu is unable to see the free space at all. In fact, as I have shown in the snaps, it is unable to see any partition and thinks the whole HDD is free. So, using fixparts should do the trick? –  Darth Coder Apr 28 at 0:49
    
Load fixparts and use ? for list to commands & p to print partitions. best to review commands from fixparts site. If you do not do the w to write changes it will not do anything. But you need to remove the gpt data. sudo fixparts /dev/sda –  oldfred Apr 28 at 4:01

I had a similar problem with Vista and eventually resorted to using Windows own built-in partition manager on the basis that they probably know best about their own file systems.

To find the well-hidden programme type partition in the search box. The latest version has options to swap between MBR and GPT and vice-versa so I think if a simple disc check does not reveal any error then (double)swapping to reinstate the appropriate tables may help.

Forgive me if this is too simple or you have already investigated this potential solution but I have overlooked the obvious many times in my career in computing.

edit:

  1. Log in to Windows
  2. Click the Start or Windows symbol
  3. Type "partition" in the search box (without "")
  4. Click on Mini Tool Partition Wizard (Home Edition on mine)
  5. When loaded the Operations column has "Convert $1 to $2" option where $1 & $2 = MBR OR GPT depending on your current system OR
  6. Click on Disk from top bar
  7. The two operations are shown with the available one clickable and the unavailable one greyed
  8. Carry on from there

I have not used this on W7 or W8 but as it is a Microsoft provided programme they would offer support to anyone with a registered MS installation.

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Whoa I did not know that one could switch between MBR and GTP! Can you tell me how to do it in Windows Disk Manager? It might just solve my problem! –  Darth Coder Apr 26 at 3:55
    
Sorry I couldn't find the Operations Column. I had added a snapshot of how my partition tool looks like. Could you guide me based on that? –  Darth Coder Apr 27 at 16:46
    
The screen shot is MS own DM. if you did not find the MTPW in your installation it is here link –  user265064 Apr 28 at 9:39
    
Windows only boots from gpt partitioned drives with UEFI and has needs for extra partitions. Usually better to install Windows in gpt with UEFI. You can use gdisk to convert from MBR to gpt or vice-versa, but have really good backups and understand the limits of each. rodsbooks.com/gdisk/mbr2gpt.html –  oldfred May 1 at 22:14

I would try, after making a backup of the system :), to use Testdisk and see if it can recover your partitions. It has worked for me in the past with deleted or wrongly formatted partitions. You can install it in the live system.

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+1 for the backup. –  landroni Apr 26 at 7:48

If you a truly looking for a dual boot solution with "with minimal hassle" I submit that you could simply use the wubi installer.

The WUBI installer is on the 14.04 ISO and works with windows up to 7.

Just pop the disk in while running windows 7.

See Windows installer for Ubuntu 14.04 LTS

Many of my clients have found this an effective way to use Ubuntu when they were either unable or unwilling to dump Windows entirely.

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@Darth Coder The wubi installer will setup space and a filesystem for Ubuntu in a file in your windows 7 installation –  Elder Geek Apr 30 at 19:17

Go to ubuntu start (at the top right) and search for disks. Open disks and create a partition over there or if you already have one format it. Ignore any errors. (This step is via Try Ubuntu mode).

Now you can see the partitions which you created while selecting partitions.

NOTE: Always backup each piece of data while doing anything.

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First change hard disk connector (in my case from connector2 to connector1). Some SATA ports have different controllers on the motherboard. Often times these extra ports are for eSATA, SATA3, SATA6, etc. When these ports are operating in new-ish modes then it is possible that Ubuntu wont understand how to use them. So by switching SATA ports and changing the bios modes (of operation) to the most universal (AHCI or so) often solves these types of problems

Second free some space in your hard disk and let that space be clean (unallocated space). Now try to install Ubuntu again and I believe that it will detect all the partitions and the free space as well. Use the tool that is provided with the installer (under the "Something Else" option) to create the partition that you need to install Ubuntu.

The solution that I have presented is working for me and is based upon the articles in these links (that you can check for more details):

link1

link2

Hope this works for you

JaMmedSyS

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