Network Domain. Enter the DNS domain in which your server is or will be registered in. For example, if your server's full DNS name is server.mydomain.net, you would type mydomain.net here.
Server Name. Your server's full DNS name. From the example above, you would type server.mydomain.net here.
Administrator's Email Address. Enter the server administrator's or webmaster's email address here. This address will be displayed along with error messages to the client by default.
For whom to install Apache Select for All Users, on Port 80, as a Service - Recommended if you'd like your new Apache to listen at port 80 for incoming traffic. It will run as a service (that is, Apache will run even if no one is logged in on the server at the moment) Select only for the Current User, on Port 8080, when started Manually if you'd like to install Apache for your personal experimenting or if you already have another WWW server running on port 80.
The installation type. Select Typical for everything except the source code and libraries for module development. With Custom you can specify what to install. A full install will require about 13 megabytes of free disk space. This does not include the size of your web site(s).
Where to install. The default path is C:\Program Files\Apache Software Foundation under which a directory called Apache2.2 will be created by default.
During the installation, Apache will configure the files in the conf subdirectory to reflect the chosen installation directory. However, if any of the configuration files in this directory already exist, they will not be overwritten. Instead, the new copy of the corresponding file will be left with the extension .default. So, for example, if conf\httpd.conf already exists, it will be renamed as conf\httpd.conf.default. After the installation you should manually check to see what new settings are in the.default file, and if necessary, update your existing configuration file.
Also, if you already have a file called htdocs\index.html, it will not be overwritten (and no index.html.default will be installed either). This means it should be safe to install Apache over an existing installation, although you would have to stop the existing running server before doing the installation, and then start the new one after the installation is finished.