exploits. But not all applications are DEP-compliant and some will generate DEP exceptions. Therefore, DEP is not enforced for all applications by default in 32-bit versions of Windows and is only turned on for critical system components. Windows XP Service Pack 3 introduces additional NX APIs that allow software developers to enable NX hardware protection for their code, independent of system-wide compatibility enforcement settings. Developers can mark their applications as NX-compliant when built, which allows protection to be enforced when that application is installed and runs. This enables a higher percentage of NX-protected code in the software ecosystem on 32-bit platforms, where the default system compatibility policy for NX is configured to protect only operating system components. Windows Firewall Windows XP RTM introduced the Internet Connection Firewall. It was later upgraded to Windows Firewall in Windows XP Service Pack 2 with support for filtering IPv6 traffic as well. By default, Windows Firewall performs stateful packet filtering of inbound solicited or unsolicited traffic on all types of network interfaces (LAN/WLAN, PPPoE, VPN, or dial-up connections). Like Internet Connection Sharing, the firewall has a location-aware policy, meaning it can be disabled in a corporate domain but enabled for a private home network. It has an option to disallow all exceptions which may be useful when connecting to a public network. The firewall can also be used as the edge firewall for ICS clients. When the firewall blocks a program, it displays a notification. Excepted traffic can be specified by TCP/UDP port, application filename and by scope (part of the network from which the excepted traffic originates). It supports port mapping and ICMP. Security log capabilities are included, which can record IP addresses and other data relating to connections originating from the home or office network or the Internet. It can record both dropped packets and successful connections. This can be used, for instance, to track every time a computer on the network connects to a website. Windows Firewall also supports configuration through Group Policy. Applications can use the Windows Firewall APIs to automatically add exceptions. Windows Security Center Windows Security Center provides users with the ability to view the status of computer security settings and services. Windows Security Center also continually monitors these security settings, and informs the user via a pop-up notification balloon if there is a problem. The Windows Security Center consists of three major components: A control panel, a