Right click on your language bar icon that is in the system tray, and un-check "Auto adjust"
This was a simple way of doing it that I knew and practiced long ago. The problem is that I have programs in Greek, Latin, Romanian, and with this setting enabled, I can keep the different language in different applications. The only app that contaminates the other apps is e-sword. So my problem comes when e-sword asked me some time ago if I agree that it can take control of changing the system language. And I was hoping that you could help me find a solution to undo this setting.