this looks to me as if there is something in your browser setting which forces Quicktime to be associated with the download type file.
Does this happen always?
With which file type (extension) does it happen (perhaps zip)?
In Internet Explorer, go to TOOLS and FOLDER OPTIONS and click the tab FILE TYPES...have a look (will be a long list) with which file-types QuickTime is associated. You have a chance there also to alter the association.
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