Introduction:
DotnetNuke is a web content management system (CMS) based on Microsoft .NET for building websites with dynamic content. DotnetNuke is written in C#. Though DNN has professional and enterprise editions, community edition is open source.
DNN comes with its core modules and many of them are very helpful to fast development. You can extend your DNN website with 3rd party modules or with in house custom modules.
In this article, I am going to show you step by step procedure on how to install DotnetNuke 7.1.2. The same installation procedure could be applicable to earlier and future versions of DotnetNuke.
Prerequisites:
In order to succeed your DNN installation, your development PC should meet the following Requirements. Your machine should meet these requirements if you are installaing DNN 7.x or higher version.
Operating System: Windows Vista/7/8.x/2008/2012
.NET Framework: v4.0/v4.5
IIS: v7.x/v8.x
SQL Server: 2008/2008 R2/2012/2014 (Express Editions also would be support)

Installation:
The first step to do before starting the installation is get the DNN website build from http://dotnetnuke.codeplex.com/. Let’s download the website build by clicking ‘download’ button.

A file with the name of ‘DotNetNuke_Community_07.01.02_Install.zip’ would be downloaded to your Downloads folder of PC. Once after completing the download, go to the Downloads folder and Extract it:

After extracting the .zip folder, copy the extracted folder to IIS web root path. And rename the folder to DotnetNuke.
IIS Web Root Path: C:inetpubwwwroot

After renaming the folder, we need to set the necessary permissions to this folder in order to access the files smoothly by IIS. The following permissions to be set to the renamed folder:
Permission Name: Everyone                  –>    Permission Access: Modify
Permission Name: Network Service    –>    Permission Access: Full Control

Now the DotnetNuke website build is ready to host it in IIS. Before hosting the website in IIS, we need to perform one more step in SQL Server to start the actual installation.
Go to the SQL Server Management Studio and create an empty database called ‘DotnetNuke’. This empty database is needed for the installation to run the DB Scripts for DNN website.
Note: As you observed that, I have given the same name called ‘DotnetNuke’ to the website folder name and database name. But, you can give different name on your own choice.

Note: If you are using SQL Server Express, you don’t need to make any changes to web.config file as mentioned below, else you need to change connection string in web.config file.
Once you have done with creating an empty DB, open the web.config file which is located in IIS web root (C:inetpubwwwrootDotNetNukeweb.config) and change the connection string as shown below:

Now we are ready to start the installation as we finished the necessary steps.
Let’s go to the IIS by doing Win+R -> inetmgr
In IIS, under the ‘Default Web Site’, you can see a folder called ‘DotnetNuke’ (This folder would be visible here as we placed the DotnetNuke website build under IIS Web Root Path).
The next step is convert this folder as IIS Application by right click on ‘DotnetNuke’ folder and click on ‘Convert to Application’.

When you click on Convert to Application, it will open up a dialog and there you can choose Application Pool which is targeting .NET CLR v4.0 and click on Ok button.
Now you can see the ‘DotnetNuke’ folder is converted as an IIS Application under ‘Default Web Site’ of IIS.
Now we are done with hosting the ‘DotnetNuke’ website in IIS. It is time to access the hosted DNN website.
When you access the DNN website for the first time, website will starts the installation which includes running required scripts in DB for the website, creating the host user, creating the first portal, etc.
Let’s access the DNN website with this URL: http://localhost/DotnetNuke/
Note: If you give your own name to DNN website folder under IIS web root path, you need to give the same name in the above link instead of DotnetNuke.
When you access the above link, DNN installation page would be open. Installation process will be complete in two steps.
In the first step we need to provide the host account information, first portal/website information and database configuration details.

Once you fill up all the required input fields, click on continue and you will enter into the second phase of installation.

At this time you need to be wait for few seconds till DNN installation was completed. Once the installation was completed, click on Visit Website button.

When you click on Visit Website button, you would be redirected to website’s home page and also you are automatically login with host user account.

BINGO!!!! You are done with your DNN installation and you are ready to access your website, creating/managing websites, managing users, etc.
The other way to install the DNN is using Microsoft WebPI.
If you have face any issues while installing or having any queries on DNN, you can discuss them at DNN forums.
In my next article, I will try to brief on building the custom modules in DotnetNuke, publish & packaging and distributing modules.