Not sure where you got your demo version from but suggest you download Mach from "Downloads"  at the top
of the sites page. Here is a link.

http://www.machsupport.com/downloads.php

Placing your lic into the folder where Mach was installed shoud have worked. You should get an English screen when it opens.
To change to an English screen, when in Mach click ---------- View>Load Screens> then select 1024.set ( should be a Mill File).

RICH