Even as root, you cannot create a file on the ntfs partition, and you cannot copy a file to it. Why?
Well install ntfs-3g.
sudo pacman -S ntfs-3g
and when it installs it tells you 2 things that you should not be afraid to do. The first is run modprobe from the command line. This command runs instantly with no problems, hassles. And the 2nd is to modify a conf file. Don’t worry because as soon as you do the pacman command it tells you very clearly how to do these.
Now when you mount your volume you can
sudo mount -t ntfs-3g /dev/sda7 /home/louie/documents/prog
That’s all. Make sure to leave a comment just to send some love 😉