Windows + Ubuntu dual boot : boot loader problem

After trying to uncover my newly installed ubuntu as dual boot with a previous windows installation without much success I finally came to this easy and simple solution.
With boot-repair ou can quickly restore your newly installed linux os by typing the following commands...:

1. Boot from your live CD/ Bootable USB and choose the option try ubuntu.
2. CTRL + ALT+ T to open a new terminal
3. $ sudo add-apt-repository ppa:yannubuntu/boot-repair
4. $ sudo apt-get update
5. $ sudo apt-get install boot-repair
6. Run boot-repair from your system or just type boot-repair from your terminal
7. On start select  Recommended Repair , then follow up ...
8.  Soon on restart you will be presented with your grub menu...
9.  That is all

Enjoy it !

Should I install Mpi on virtualbox ?

The objective of this post is not to claim that it is not possible to run open mpi on virtualbox. But I intend to warning of the potential challenges that are awaiting for you when you opt for running open mpi on virtualization especially virtualbox.
I have just wasted  some times trying to make work. Even when it works you have a limited of processors of course depending on your hardware specification. In my case I was running a 32-bit ubuntu 14 installed on a HP laptop icore 5 . and I have at most 4 processors with only 2 usable. Everything was just a nightmare.... so many other issues came up.
 If you don't have enough time and have a serious application to be developped with open mpi please you are warned don't opt for virtualbox especially if you have a normal standart hardware.
  Feel free to share your experience with us.