If the SP-2 you installed is for Windows XP, then yes you do need to
installed Office 2003 SP-1. Windows XP SP-2 updates your operating system.
Office 2003 SP-1 updates your Office applications.
As there is no SP-2 for Office 2003, if you are not referring to SP-2 for
Windows XP - what are your referring to?
No. I wouldn't go backwards. Why would you want to update an application by
installing an earlier version of the application? SP2 provides the latest
security. SP1 has more vulnerability to threats. XP Pro is an operating
system. Office 2003 is an application. You have the latest security, with
one of the latest operating systems, and the latest version of the Office
application.