Windows XP SP2: Fix or Foe? When Microsoft rolled out Service Pack 2 for Windows XP (news - web sites), it marked an important milestone for the giant software maker. The company had plowed more than six months and $100 million dollars into the SP2 super patch in an effort to resolve Windows XP's growing list of security headaches. In addition to plugging a lot of holes that hackers could take advantage of, SP2 delivered an upgraded firewall that is active by default. Just like that, millions of Windows XP-based PCs can automatically filter incoming traffic and hide resources from other systems on the Internet. There's just one problem. Windows XP SP2 can end up disabling or otherwise affecting third-party security applications you already have running. Some experts say that despite possible headaches, this is actually good news. In the past, Windows updates and patches have focused so much on maintaining compatibility that they've glossed over some security holes. The result has been that some holes in the operating system have gone unfixed for years--dating all the way back to Windows NT 3.1. Windows XP SP2 plugs those holes, in many cases at the expense of compatibility. Programs that conflict with the new service pack can experience problems that range from simple error messages to the inability to launch properly. Norton Anti-Virus 2003, for example, won't perform scheduled scans under Windows XP SP2--you have to manually perform disk scans. There are also several software firewalls that conflict with XP SP2 that can prompt an error message and cause you to reboot your system. Microsoft has published a list of applications affected by Windows XP SP2. Check this list before you install the SP2 update so you'll know whether an update to any third-party software or utilities is needed. In fact, it's a good idea to visit the company Web sites for all your important software and utilities to see if they have updates you can download. Unfortunately, once you've upgraded to XP SP2, Microsoft will do little to help you beyond telling you what you may already have discovered. The responsibility for fixing compatibility issues falls on your software vendors.