Windows XP SP2

SP2 adds new functionality to Windows XP, including an enhanced firewall, improved Wi-Fi support, such as WPA encryption compatibility, with a wizard utility, a pop-up ad blocker for Internet Explorer 6, and Bluetooth support. The new welcome screen during the kernel boot removes the subtitles "Professional", and "Home Edition" since Microsoft introduced new Windows XP editions prior to the release of SP2. The green loading bar in Home Edition was replaced with the standard blue bar, seen in Professional and other versions of Windows XP, making the line of operating systems resemble each other.

SP2 added new security enhancements, which include a major revision to the included firewall that was renamed to Windows Firewall and is enabled by default, Data Execution Prevention that takes advantage of the NX bit that is incorporated into newer processors to stop some forms of buffer overflow attacks, and removal of raw socket support (which supposedly limits the damage done by zombie machines). Additionally, security-related improvements were made to e-mail and web browsing. Windows XP Service Pack 2 includes the Windows Security Center, which provides a general overview of security on the system, including the state of anti-virus software, Windows Update, and the new Windows Firewall. Third-party anti-virus and firewall applications can interface with the new Security Center.