Is the new client broken?

[Zojha]

Is there a way to set the system to window mode or will I be forever stuck in Full Screen mode due to not being able to itneract with the game client's main menu?

Go to your start menu and search for "FFXIV.cfg" (Typically found in C:XXX/MyGames/Final Fantasy XIV, where the character data lies). Open it with a text editor. In the display settings, set ScreenMode to 0.

That sets it to windowed. Or at least, does for me. Also allows me to interact with the start menu again, so long as I'm not touching anything from that point onward.