QuickTime

Hi,
The below message is a copy of one I sent to the Jaws users list in relation to QuickTime settings with Jaws. Hope I can get some advice on this.
"I have tried to set the file associations differently in QuickTime running Jaws 14, under windows 7 64 bit so that files that I stream won’t open like a web page without a player, in other words, handled by QuickTime and/or iTunes. How can I change this setting? I have tried under mime settings in the preferences section, but I can’t even check any boxes to attempt changes to the settings."