Windows Firewall is now turned ON by Default. It also loads immediately at Start Up preventing attacks that can happen immediately when turning on your system. Previous firewalls from Microsoft loaded after other parts of the operating system were loaded.
One defect to the system is that the firewall can be turned off by third party software. ZoneAlarm, McAfee's Personal Firewall Plus and Symantec's Norton Personal Firewall are all being updated to disable Windows Firewall when they are installed, and switch it back on when they are uninstalled.
And if another firewall or an administrator can switch Windows Firewall off,
so could an attacker, argued Zone Labs. Critics also said the firewall should
have included outbound blocking, used to stop malicious code from being used
in a distributed denial-of-service attack or to send spam, for example. Zone
Alarm does this. Why is out bound blocking important? Well most viruses and
other maliciously produced software can come into your system via regular and
open channels. For instance you can get infected by your own action. Say for
example you download some malware via a link in an email you get that says:
Click here to Update your account information.
It could be the case that while a page is opening, Internet Explorer is allowing
various bits of code to be installed without your knowing. Once this software
is installed and you are connected to the internet the malware could start
using your address book and its own email sending engine to generate thousands
of emails being sent out bound. Another example could be that the malware already
resident on your computer could go out on your LAN and search for open shared
folders upon which it can spread itself.