I do all my task in Ubuntu. How will I be able to remove the Windows8 using ubuntu? I don't want to see Windows8 name displayed in the grub menu. And I want Ubuntu to be started in the first hand after I boot my computer. Will it harm any files, folder and partition?
I can think of two ways of doing this.
While installing select erase everything and install Ubuntu as only OS. (First option)
Install Ubuntu alongside Windows or create separate partitions and install Ubuntu. After installing use the software grub-customizer and delete Windows entry there. Then you can manually delete Windows files.