How to Block an IP Address in Windows Firewall
Internet protocol addresses give a user the physical location of a computer sending signals or messages to her computer. If an IP address is trying to hack your computer or keeps sending messages to your system, you can use the Windows Firewall to block that IP address. You don't have to be a computer programmer to block the IP of another computer. You can do it with little hassle and in just a couple minutes of time.
Click the "Start" menu and go to the "Control Panel" from the menu.
Go down to the "Security" button and click on the "Windows Firewall" option. Click the "Exceptions" tab.
Name the "Exception" with something like "Blocked IPs" and then enter the port number your cable modem or wireless router is using. You can look this up in the owner's manual that came with your modem or router.
Click the "TCP" button to block incoming data from reaching your computer. Click the "Change Scope" button and type the IP address you want to block.
Click "OK" to save your changes.