Added support for stronger wireless encryption standards, moving beyond the easily compromised WEP.
Improved native support for high-speed USB devices without needing third-party manufacturer drivers. Professional Edition Capabilities a pop-up blocker for Internet Explorer
: SP2 was the major update that introduced the Windows Firewall , a pop-up blocker for Internet Explorer, and memory protection against malicious code. Serious Risks & Drawbacks Microsoft Windows XP SP2 review - CNET a pop-up blocker for Internet Explorer