To update Microsofti Office online, Click on the Start menu, and choose "Windows Update" from the menu.
Once the page loads, just under the "Windows Update" blue banner there are "Home", "Windows Family", "Windows Marketplace" and "Office Family".
Click on "Office Family", and a new window will be opened which is the Microsoft Office online update.
Click on the "Check for Updates" link, and your system will be checked for updates.
If you have Windows XPi with Service Pack 2 installed already, you may need to follow this information on allow the installation of an activex control on Windows XP Service Pack 2.