What window a PDF is loaded into, _self or _blank, changes IE's behavior ... could this be a source of confusion in this thread? -----Original Message----- On Behalf Of Hershel Robinson what is the > original problem, in the least words possible? RForcing a download of a PDF? PHP script to read a PDF file from disk and deliver it to the browser and have IE7 / Windows XP understand that it is a PDF file. > Has anybody suggested the MIME type application/unknown? I see no reason to expect that to work. Sincd the file is being read by PHP and then fpassthru'd to the browser, the .pdf extension is not seen by the browser.