Unable to Upload File

System

One of my users (an AUTHOR) cannot upload files - wants to upload a word document.

I suspect one of the ActiveX controls is missing. When user select File Upload from the TeamSite menu the left panel goes blank and just sits there - nothing happens - The left panel should contain the File Upload page to select/add and upload.

How can I force Teamsite to prompt user to re-download the ActiveX control - if indeed that is the problem ?