How to prevent other hosts from accessing a certain port of the machine in the Windows 7 system

When the Win7 system shares files, you do not want others to access other port contents through this port. The win7 system's firewall can be used to prevent other hosts from accessing certain ports of the machine.
First understand the inbound rules and outbound rules: inbound is when someone visits you, and outbound is when you visit someone else.
Open “Control Panel”-"<quo;System and Security"-"  Click "“Advanced Settings" on the left panel; "Advanced Security Windows Firewall" window:

Click on the "Inbound Rules" on the left side and click on the "New Rule" on the right. ”, select “port”:

<;next” after selecting protocols and ports, such as TCP and 4000 ports:

“Next”after selecting“ Block the connection>:

Next, choose as needed:

Last, set the name, click “Complete”:

The firewall will enable the new rule by default. .