Scenario : You have a PC which already has any of the flavors of Windows 7 installed. You would like to Dual boot the system with Ubuntu 14.04 LTS. Ubuntu LTS editions are good in the sense they come with guaranteed support for up to 5 years of updates, bug-fixes and feature additions.
Before we begin, let me clarify a small point. When we normally go via the process of Ubuntu installation after windows 7 has been installed on a PC, Ubuntu will erase the MBR (Master Boot Record) of windows and will install GRUB 2 (the Linux bootloader). This is fine to an extent and you will get options like below for selecting which OS to log into :
The installation in this approach is straight forward you get a side by side install option and rest everything is fairly automated. However, this ease comes with a catch.
The problem : When Microsoft sends updates to Windows; at times some updates are so that they will replace the GRUB loader with Windows MBR and you will lose the ability to select the Ubuntu OS, then you have to again manually edit the Windows loader. Doing this can become tedious and irritating. Thus comes our better approach.
What we want : If we can keep the Windows MBR as the default bootloader and manage to insert Ubuntu entry to the windows loader; it will be convenient and fool-proof in the long run.
This ugly looking windows loader is going to be our choice 
Requirements
- Pc with windows 7 already installed
- A copy of Ubuntu Linux 14.04 ISO [ can be obtained from here ]
- If you want to burn a DISC [Ubuntu ISO above downloaded] go ahead and waste your money and time, I would suggest using a Pen-Drive [2 GB is enough]
- If you go by my advise; then we need another little software UNetbootin [ Job is to convert the ISO into bootable Pen- Drive, Grab it from here ]
- Finally another little software called EasyBCD[ get it here , from official page you cannot get it ]
Steps
1 Pre-preparation step [ To make space for Ubuntu by shrinking the Windows 7 drive ]
Right click “My Computer” then Choose Manage, go to disk management, you will see the following :
Now right click on C: Partition and click on shrink volume, it will take some time and calculate available space which can be shrunk, depending in how much you are going to use Ubuntu and what type of usage you envisage for yourself you can allocate space. Minimum 20 GB is good enough but if you really want to get into the groove with Linux you can choose a sumptuous amount of memory and Ubuntu is so good you will love it [ Except for Photoshop
and some games everything else is there, it is free and fast ]. Do not format the newly unallocated volume , we will do that during the Linux installation.
Steps towards Ubuntu installation :
- Fire up UNetbootin by right clicking and run as administrator , then do the following as shown in the image below :
Once you have selected all the options as instructed click ok, it will take about 10 mins, then simply close the UNetbootin window
- Restart the computer with the pendrive plugged into a USB port and while the PC restarts press F12 , or F2 [For one time boot menu selection like on Sony or Dell or HP ], if for some reason your PC BIOS does not support one time option then hit Delete button and go to BIOS setup and enable boot from pen-drive or external disk drive [ Whatever they may call it ]
- Now if all goes well you will see the following screen :
Click on Install Ubuntu
Next up you will see this window
Click on continue
Next up you will see this
This is an important step , look at the instruction in the image and do accordingly [ Select the something else radio button , that is it ]
- Next important repetitive steps with subtle variations [ Pay attention to images ] , The above step would bring an advanced partitioning tool which can be used as follows
Click on the + icon and this will display the following screen
We need 3 partitions for Ubuntu btrfs file system 1 ) /boot 2) / 3) swap area
Let’s create boot partition first
Make sure Ext4 and /boot is selected, 300MB is minimum and you can increase it to 500MB actually and hit ok
From here for the rest two we iterate the same procedure
we hit the + button again and
Create the Swap Area [ as soon as you select swap area the other option will go
] , 2000 MB or 2 GB is enough for SWAP area
Next we again do the same for the root [ / ] partition
We hit the + icon for the third and final time
We can allocate the rest of the space which was unallocated and and choose btrfs journaling file system and mount point as /
Once we are done with this the next step :
- Care fully select the dev/sda5 for the grub installation else we will have a problem [ so we are going to install it for the 300MB boot partition or any other amount if you chose a different amount ]
See in this large image how dev/sda5 is chosen and then Install now is hit
Now you will see the following screens in sequence :
choose your time-zone by clicking on the map
continue
this is fine for most people and just click continue
here create a username and password and click continue
finally with this screen Ubuntu will get installed
Next take-out the Pen-drive and restart, you will be surprised we will directly log back into windows 7 only and Ubuntu won’t show; hold on that is because one last step is pending we have to log into windows and do that last step.
Fire up EasyBCD by right clicking and running as administrator, once it is installed just run it
As we can see at the moment the bootloader has only entry for windows 7 , we will fix this by clicking on Add New Entry
We will chose the Linux/BSD tab and make sure Grub 2 is selected Name can be Ububtu 14.04 and drive should be the dev/sda5 [285MB if you chose 300] , then we will save it by clicking add entry
That’s it folks when we reboot we will get out option
Wow
Thank you
shakeel osmani 