Office Update won't update 2003

Whenever I go to the Microsoft Office downloads page, and click on check for updates, I get an error

Office Update is unable to check for updates Help
 
The Office Update site is unable to check for updates on this computer. This may be happening because of one of the following reasons:

>You do not have administrative privileges for this computer.

I am using the main account in XP Pro, which is set as an administrator.


>There is a network problem and the detection catalog used by the Office Update site failed to download. Go back to the Downloads home page and try running detection again.
Windows Installer patch files (.MSP files) from previously applied Office updates are missing from the \Windows\Installer hidden directory on your computer. MSP files are stored on your computer after update installation completes because they need to be referenced for future update operations. If the files are missing you will not be able to apply Office updates. You may also be unable to uninstall Office products as a result of the same problem. Please contact Microsoft Product Support Services for assistance.


>You installed Office updates in the past and then upgraded from Windows Installer version 1.0 to Windows Installer version 1.1. For more information see the KB article Windows Installer May Prompt for Install Source if Unavailable.
 

I am wondering if it's one of the above two - I notice that whenever a new email is being opened, an Installer window briefly appears.

When a large email (2.3 MB) was being downloaded in the only account (POP), Outlook froze.
I did notice the Installer window (without any information, just a message saying that the Installer is working) as having been opened.

I have run a detect and repair, and installed ALL Office 2003 components to run on the computer.


I realize that the installer window shouldn't be appearing every time a new email is received.


Thanks