When users go to register, they then go to there email accounts to confirm registration. When they click the link, its going to a 404 error page. What can I do to correct this matter?
No it isn't good to go.
I'm having the same problem. I just tried to create a dummy account and my confirmation e-mail link was:
My URL in ACP is http://fuelinjectionbible.com/forum with no trailing slash.