I'm running the latest update of Skyrim and cannot complete the quest where Arngeir request you to shout at him. Everytime I shout at him, he acts as if it never happened and continues telling me to shout at him. I've tried entering and exiting the room, restarting skyrim, leaving for a few game days and completeing other tasks...nothing seems to work.

I've not been able to find much on this glitch by googling, so here I am. Any ideas?

Did you use the full shout on him? (As in holding down the shout button).

Yes, they fail to mention "how to use shouts"...

Tap = low-shout power
Hold for ? micro-seconds = med-shout power
Hold longer than ? micro-seconds = full-shout power

I believe you need to do the stronger one...

Are you sure you're using "Unrelenting Force" on him and not another shout? I discovered that he won't pay attention to any other shout.