Win7 system comes with a firewall introduction and how to configure problems with multiple firewall policies

Since the introduction of the first firewall (Internet Connection Firewall) built into Windows XP, Microsoft has been steadily improving the firewall capabilities of its later systems. The Windows Firewall in the latest client operating system, Windows 7, has been revolutionized to provide more user-friendly features and a significant improvement in the firewall for mobile users. In this article, we'll cover Windows Firewall in Windows 7 and how to configure it with multiple firewall policies.
The history of Windows Firewall
The firewall software in Windows XP only provides simple and basic functions, and can only protect inbound traffic and prevent any inbound connections that are not started locally. By default, this firewall It is closed. The SP2 system is enabled by default, allowing system administrators to enable firewall software through Group Policy. Vista's firewall is built on the new Windows Filtering Platform (WFP), which adds the ability to filter outbound traffic through the Advanced Security MMC snap-in. In Windows 7, Microsoft has further tuned the firewall's capabilities to make the firewall more user-friendly, especially on mobile computers, and capable of supporting multiple firewall policies.
Windows 7 Firewall
In Vista, the basic settings of the Windows 7 firewall are set through the control panel program. Unlike Vista, you can also access advanced settings through the control panel (including configuring outbound connection filtering). Instead of creating an empty MMC and adding a snap-in. Just click on the Advanced Settings link in the left panel, as shown in Figure 1.

Figure 1: In Windows 7, you can access advanced firewall settings through the Control Panel program.
More Network Options
Vista Firewall allows users to choose public or private networks, while in Windows 7 You have three choices: a public network, a home network, or a work network, both of which are considered private networks.
If you choose the "Home Network" option, you can create a Homegroup. In this case, network discovery is automatically turned on so that you can see other computers and devices on the network and they can see your computer. Computers belonging to Homegroup can share pictures, music, videos, and document libraries, as well as share hardware devices such as printers. If you have files in your folder that you don't want to share, you can also exclude them.
If you choose "Work Network", the network discovery is enabled by default, but you will not be able to create or join Homegroup if you add your computer to the Windows domain (via Control Panel