By default, Windows 7 only displays a full network map in the Network and Sharing Center if you’re connected to a Private network. The network map is a graphical view of the computers and devices on your network that shows how they’re connected. However, you can turn the mapping feature on when connected to Domain and Public networks as well.
Windows 7 gives you the ability to create a home network through which you can share resources among your home computers and devices. Home computers are normally assigned to the Home network location where such designation allows you to use HomeGroups. HomeGroups make it easier to share resources in environments where Active Directory does not exist. HomeGroups cannot be created on a domain network but you can join an existing one while you are part of a domain. For example, you could join a HomeGroup on your home network and at the same time connect to your work’s domain network through a VPN connection.
If you are planning to set up a small home network or connecting your Windows 7 machine to another computer you need to have an IPv4 standard or arrangement. Typically, you may have one computer connected to the Internet which provides Internet services to the other internal computers. Windows 7 can do this role through the Internet Connection Sharing (ICS) service. Other services or devices such as, Wireless Access Protocol (WAP) in wireless networks or DSL and cable modem routers can too provide Internet services to the internal computers. On the other hand, if you are not planning to provide Internet services then you can avoid all the trouble and let the internal computers configure themselves through APIPA.
Personally, I have never used the Windows Diagnostics Tool apart from the time when I decided to write a few lines about it. Most windows administrators would normally invoke other testing tools to troubleshoot network issues, however, for the less knowledgeable users the Windows Diagnostics Tool is an adequate solution that tries to automate the troubleshooting process. The tool button or link appears automatically when Internet Explorer cannot display a webpage.