Office 2003 Update failure

I purchased Office 2003 Professional with new 8300 Dimension last year.  On initial installation there was no "splash screen" to lead through installation process.  There were only icons for .exe, readme files, etc.  I installed by clicking on individual .exe files  Everything seemed to be working ok. 

 

 When I run Office Update I get error message:  "Office Update is unable to check for updates".

 

 I then downloaded Security Patch 1 and tried to install and got another error message: "Update cannot be applied."

 

On the "Add / Remove" screen, Office is listed as a program, but "repair" and "uninstall" functions fail as well.  Error message is the same for either attempt:  "This patch package could not be opened.  Verify that the patch package exists and that you can access it, or contact the application vendor to verify that this is a valid Windows Installer patch package."

 

When I go to "regedit" then HKey_Local_Machine\software\microsoft\windows\currentversion\uninstall there is no Microsoft Office folder.  So I can't even uninstall and reinstall application.

 

I've tried using suggestions for similar error messages on Microsoft message boards and nothing works.  Any suggestions appreciated.