I have DNN 4.9.4 installed and working on test maching and it runs when I use http://localhost.

I installed it on C:\dnn494
IIS 5.1 is points to that directory as my default website
This subdirectory has USE SIMPLE FILE SHARING unchecked.
Secuirty is set for :
ASP.Net Machine Account (Test1\ASPNET) - FULL CONTROL (everything check mark in the ALLOW column)
Internet Guest Account (TEST1\IUSR_TEST1) - READ & EXECUTE, LIST FOLDER CONTENTS, READ (check mark in the ALLOW column)

DIRECTORY SECURITY | AUTHENTICATION METHODS
Check mark - Anonymous Access
Username: IUSR_TEST1
Check mark - Allow IIS to control password
Check mark - Integrated Windows Authentication

Besides the localhost, I have made portal alias for the associate IP and machine name.
i.e.
172.24.53.53
test1

I can ping that DNN installation computer from another computer

When I click on URL listed following, it loads up the DNN main page on the localhost machine
i.e.
http://localhost
http://172.24.53.53
http://test1

But if I try to make a portal alias
i.e.
http://localhost/dnn494
http://172.24.53.53/dnn494
http://test1/dnn494

I get a "THE PAGE CANNOT BE FOUND"  using Internet Explorer
I am assuming that if I try to access the DNN from another computer within my network I would have to type in, one of these to get to it:
http://localhost/dnn494
http://172.24.53.53/dnn494
http://test1/dnn494
 

How can I fix this?

Thanks Chris for your reply.  Yes you are correct if I want to set it up that way as a virtual directory.  I went back after I my OP (Original Post) and found the solution. 

I did keep my port alias without using virtual directory option.

Port Alias
localhost
test1
172.24.53.53

But what I did to fix my problem is to go under the FIREWALL settings of Windows XP to allow PORT 80 as an exception on my TEST DNN Installtion computer.  I can finally reach the DNN site from another computer using http://172.24.53.53
 

Cheers!