But I worry you didn't try another DNS on the PC in question. Try 184.108.40.206 next on that PC.
Also, some security suites block this when they expire. I have no kind words on that and call it thuggish behavior.
I finished setting up my new router yesterday (got rid of the HH and I’m now running and EDgeRouterX and UAP lite though a Modem (vigor 120). Everything was working fine for 24hrs and then when I boot up my PC I could not access the internet (I could still access the ERX’s web interface however and access the internet’s on other devices). I have narrowed it down to a DNS problem, so please ask for what ever info you need, I just MUST get this sorted.