Determining the Service Pack Installed in Office

To find out what version of Microsoft Office Service Pack is currently installed, click on Outlook (for example) Help menu and About Microsoft Outlook. The service pack version is indicated by the word ‘SP’ next to the Outlook version number.

For example,
Microsoft Outlook 2000 (9.0.0.2711) SP-1a is service pack 1a
Microsoft Outlook 2000 (9.23.1285.131) SP-2 is service pack 2
Microsoft Outlook 2002 (10.2340.4560.21) SR-1 is Office security update and not a service pack