I don't know if it'an issue on my side, but I have not manage to do anything with the :terminal on Windows 7. It starts a prompt but I can not input anything in Terminal mode. I tried 'i' to go in insert mode in the terminal but it does not seem to work either. (To be sure this is not something in my vimrc, I tried with and without it). At that point I am not sure if this is a problem between chair and keyboard or a bug.