Cannot talk in Linkshell chat

[Coldfire]

I tested that yesterday on my laptop, and I can confirm that the game functions properly on my laptop. So it is just on my normal PC that I cannot talk in LS chat.

You should try the usual stuff then:
-Move the ffxiv folder inside your documents/my games/ to desktop and run the config again
-If that doesn't work a complete reinstallation might be necessary
-Run a checkdisk as ffxiv seems to have the habit to break the filesystem