How to install ubuntu in dual boot mode using an USB drive ?

1. Create a ubuntu bootable USB stick    

    Using http://codesearching.blogspot.in/2015/12/how-to-work-on-ubuntu-without.html

2. Boot using USB drive

    a. Restart PC, Go to BIOS by pressing F2/F8/F10 according to your PC model.
    b. Go to Boot sequence and set "External drive" as first boot preference.
    c. Restart PC so that it will boot by USB

3. Install setup

    a. After boot, Choose the option : Install ubuntu and press Enter

    b. Choose language = english

    c. Choose wireless network , if wifi available for internet access

    d. Choose installation type :

        Install Ubuntu alongside Windows : Install Ubuntu with keeping Windows intact

        OR

        Erase disk and install Ubuntu : Install Ubuntu by formatting disk & Windows installation

    e. Select drive

    f.  Select location = New Delhi

    g. Select keyboard layout = English (US)

    h. Provide user details and password

Installation will be started.