Before you start, please refer to this Knowledge Base article to ensure that your site meets the basic requirements for DotNetNuke to run smoothly on our servers.
The first step is to create a MS SQL database in Control Panel.
Then go to your Winhost Control Panel, and under "Site Tools" click the App Installer button.
Find DotNetNuke in the App Installer and click "Select this Application >>."
To install DotNetNuke directly in the root of your site, make sure the "AppPath" field is left blank.