You are still installing mojoPortal under a virtual directory beneath a web site instead of in the root of the web site. If you instsall it as a root level site there not be a folder like /mojoportal involved.
I feel like I've explained this pretty well in articles and videos I've given you links for in previous posts, but I just updated the article Adding a Host Name to the hosts file for local testing with some more background information. Maybe that will clear it up for you.
Hope that helps,
Joe