If you are running 32-bit xp you can install service pack3 and continue with support. If you are running 64-bit XP this operating system is now “dead”. No more patches of any kind. All versions of Windows 2000 are also now End Of Life. You need to move to Windows 7/server 2008 now before your systems become even bigger targets.
Support for Windows 2000 and Windows XP SP2 comes to an end.