Upgrade only; previous version of XP required Get the most out of your operating system, and avoid the bugs that can slow down your computer's performance. This upgrade combined with the newest Service pack delivers the enhancements you need for a faster, more capable PC. Security Center offers a central control system for your Windows XP security -- work with the firewalls, auto updates and antivirus tools Great news for people sick of pop-up ads - The built-in pop-up blocker controls them, with a new submenu and status bar icons The new Add-Ons manager gives you instant access to all the Browser Helper Objects and extensions, enabling and disabling them easily The firewall now has its own control panel, for customizing firewall setting to suit any connection Enhancements to the Windows Update service make installing new updates easy -- you can even choose which ones to install, if any Wireless Networking - Multiple wireless connections to choose from