Here's what always works for me:

Install IIS
Install ASP.NET 2.0 framework (and SPs and Updates, etc.)
Install SQL/SQL Express
Create the site in IIS
Create a VDir if you wish, you can also put DNN in the web root
If you create the VDir, set it as an application and set it for ASP.NET 2.0 (The root is aready an app)
Set the NTFS permissions on the web folders to allow MODIFY permission to the ASP.NET process account (depends on OS)
Create the SQL database and a login (if you're using one) and set the login account as DBOwner
Upload the Install files (not source) to the site/VDir
Edit the web.config to the correct connection string (if needed)
Hit the web site with IE and start the install wizard
Enter appropriate info in the wizard as needed
When the wizard completes, click on the "click here to access your portal" link

Try the various installation tutorials and videos.  Make sure you read the documentation.  Make sure you use the install package, not the source or starter kit.

Jeff

Well I did finally get the 4.8 source installed. 

if you get into trouble installing the source for 4.8. 

Make sure you get the rules down.   I tried one attempt by memory which seemed to created a website from the source folder but put the site in a seperate folder called DotNetNuke_2.  it worked but when i opened the folder with Visual Studio the source files were not in there!  I copied over the source files. I thought that was weird and not what i wanted.  so I went to where I should have the first time.

http://www.adefwebserver.com/DotNetNukeHELP/DNN4_DevelopmentEnvironment_Source/

Still none of this worked either.  

i recieved several errors along the way.

Line 89:             Initialize.StopScheduler()

Line 67:             If Config.GetSetting("ServerName") = "" Then

and a few more.  

I found the link below interesting in and of itself.  It made me start renaming the alias to DotNetNuke_2.  Which made sense to me because my first attempt created the dotnetnuke_2 site for me and it worked right off, but I wanted the source code install.   

I first tried changing the path in the IIS folder to go to my new source folder.  I also change the path directory using notepad in the solution file to match the alias DotNetNuke_2

That just gave me more errors.  so i deleted the IIS websites and attempted to try a few more times.  Still no sucess.  

 woke up with a clear mind and said, clean out every single solution, website folder and SQL database that did not work. 

That was it.  As i was cleaning it out I noticed that first install solution and another solution were pointing to the DotNetNuke_2

Which is an important step in my first post on this.  Go to bed.  

Like with people, Communication with the Server is not what you say but what is heard.  Servers pick up what I like to call non-verbal communication. 

Your old failures will hurt you.  Clean them out, start fresh, move on.   PLAY! 

http://www.dotnetnuke.com/community/blogs/tabid/825/entryid/240/default.aspx