The windows firewall service is included with most desktop and server releases with windows XP and onwards. It protects your computer by blocking connections that could in reality be unsafe software trying to find a way to connect to your computer. Windows Firewall is smart enough to allow connections from computers in your home and to block those connections from computers on the Internet. Windows Firewall will permit you to distribute files or a printer among two computers in your home, but it will wedge any attempts from people on the Internet who might try to connect to your computer. Although the firewall will offer some protection from network attacks and malicious software, it will not protect against viruses or spy ware.
Standard Guide for Windows Firewall to Confirm Protection
Click “Start”, and then click “Control Panel” and then click “Security Centre”. If Windows Firewall shows “ON”, you are protected. If Windows Firewall shows “OFF”, it has been disabled. If you have another firewall installed, this is probably OK. However, if you don’t have another firewall installed, you will need to re-enable Windows Firewall from within Security Centre. 