I encountered a strange problem while trying to install Ubuntu 14.04 on a box where a fresh Windows 7 is installed.It’s 1 TB hard disk partitioned into 6 drives. The Ubuntu installer doesn’t show any partition it just showed the whole 1TB as blank one partition. The installer also didn’t detect the Windows 7 installed on the system usually the installer used to detect windows and suggests to install alongside with windows.
So i quit form the installer and continued on the live session.After some googling i found this solution
The system may report that the disk contains a GUID Partition Table (GPT), which is left behind on a disk that was once used as a GPT disk but then incompletely converted to the more common Master Boot Record (MBR) form. In such situation, the system cannot recognize the partition of Windows. All that the system can see is the whole volumn. If you want to dual boot you can acheive that by removing the GPT data.
Use FixParts to remove GPT data
FixParts is intended to fix is a disk that shows no partitions in GParted or similar tools, although you know the disk to contain partitions because they’re visible to the Linux kernel or to other partitioning software.
Open up a terminal in live session.
sudo apt-get install gdisk
First backup your current partition table
sudo sfdisk -d /dev/sda > partition.txt
Where dev/sda is the partition you want to modified (backup). Next time when you want to restore the partition table, you will be able to recover your partition table by reversing the program.
sudo sfdisk -f /dev/sda < partition.txt
To see the drive’s
Delete the GPT data
sudo fixparts /dev/sda
The first check that the program preforms is for stray GPT data. If it finds lefeover GPT data, it warns you of this fact and ask you what to do:
NOTICE: GPT signatures detected on the disk, but no 0xEE protective
partition! The GPT signatures are probably left over from a previous
partition table.Do you want to delete them (if you answer 'Y', this
will happen immediately)? (Y/N):
Now you can delete the GPT data by simply type Y.
That’s done. Back to your installation and see if the system can find the previously installed Windows partitions.
Now we can see windows 7 partitions on Ubuntu.