Does anyone know why this occurs?  Once it does, it I try and back up a step and the continue again, it merely shuts down and either says "DotNetNuke is already Installed on this system", when it's not completely, or it redirects back to the home page where it give the old error:

Domain Name [domain] Does Not Exist In The Database

I'm the web host, so I manage the server.  Normal ASP.NET applications work fine.  What do I need to do to make DNN install without any issues?

Thanks.

Yes, I did and most of the results weren't helpful.

But I finally got it to install.

Here's what I did:

1. I removed all the files in the root of the DNN installation, and replaced them with clean files.  (The folders were unaffected so I could keep them there)  Make sure you DELETE all the files in the root of the DNN installation, don't just copy new clean files over.  DNN makes three new files during it's installation and they will still be there if you just copy new clean files over.  So you need to delete them all and copy back in just the clean files to make this work.
2. I logged into SQL Server and removed all Tables, Views and stored procedures.
3. This next step I missed before: In SQL Server 2005, 2008 - Expand "Programmability", then expand "Functions". Delete all functions in, "Table-valued functions", and "Scalar-valued Functions".
4. Open your site in a browser and you should see the beginning of the Install Wizard.  Then continue from there and you should be good to go.

The part that was failing for me was when it got to the page to install the database.  I would get the "undefined = Success" infinite loop.

Once I cleared out the database and also replaced all the files in the root of the DNN installation, everything worked as it should.

I can't guarantee that everything will work in every situation, but this worked for me and I hope it works for others.  I wouldn't wish this torture on anyone.

Until I tried out this new process, I was close to using Joomla.  (Personally I think Joomla is outstanding, but being a .Net guy I wanted to use DNN)

That didn't solve my issue with the loop and nothing has so far. I have tried every suggestion for every issue I have had trying to get this thing installed and have not had success to date. I know this is a community project, but if I had payed for this thing I would be pissed as hell. I have wasted far too much time with it and it is time to move onto something that does work.