I created a virtual directory for the Default Site in IIS that referred to the directory where my web site was located.
Everything was working well, since the Default Site listened to Port 80, the web application was working correctly.
At some point, Sharepoint was installed on the server on which I was working, disabling the Default Site, and enabling "Sharepoint - 80" which listens to Port 80.
It does not seem that there was any other configuration done with Sharepoint, other than installing it.
What's the correct method of adding an already existing website that was created separately from Sharepoint?