Configuration:
https://github.com/mcandre/dotfiles/blob/master/.vimrc
System:
* Vim 7.4 via Chocolatey
* Windows 10 Professional x86_64
What Vim version does Chocolatey publish? Check your :version output in Vim for the exact patch level.
I don't see the behavior on my Windows 7 PC so it's probably something in your configuration, or in the system .vimrc which may come installed by Chocolatey, if it does that.
I don't see anything that jumps out in your .vimrc, although you do seem to be setting 'nocp' rather late in your .vimrc, when normally it comes near the top. And it's not really needed if you have a .vimrc anyway.
I suspect something in your plugins, or in the system .vimrc, is setting the 'lines' option. See the output of ":verbose set lines?" in Vim to see what it is (or if I'm wrong and that's not the issue after all).