Enable VIM to access system level clipboard

On Windows set:

set clipboard=unnamed

On Linux or mac set (vim 7.3.74+):

sudo apt-get install vim-gnome
vim --version | grep '-clipboard' # check clipboard has a + 

~/.vimrc

set clipboard=unnamedplus

https://stackoverflow.com/questions/3961859/how-to-copy-to-clipboard-in-vim