Microsoft have released Office XP SP1.This is the first service pack for Office XP, SP1 will be the first major update to Office XP since the suite launched last May, and contain numerous bug fixes and security updates. Product activation changes have also been made to prevent a user from having to reactivate unnecessarily.

Download Microsoft Office XP SP1

The Microsoft download center is showing the link as Office Hotfix Installer but the link is dead :D LOL but it should be ready soon. so for now u the link above