You can use the content-disposition header to override this default behavior. Its format is:
Content-disposition: attachment; filename=fname.ext
When Internet Explorer receives the header, it raises a File Download dialog box whose file name box is automatically populated with the file name that is specified in the header. (Note that this is by design; there is no way to use this feature to save a document to the user's computer without prompting him or her for a save location.)
There are two ways that you can use Internet Explorer to specify a content-disposition header for a file: dynamically and statically.
To apply the header dynamically, create an Active Server Pages (ASP) file that writes the document out to the browser. Use the Response.AddHeader method to add the content-disposition header. For example:
Response.AddHeader "content-disposition","attachment; filename=fname.ext"
To apply the header statically, right-click the document in the Internet Service Manager, and then select Properties. Select the HTTP Headers tab and enter the content-disposition header there. This works best when you only want to apply content-disposition to a few files on your system and don't require the overhead of ASP.