I have all my images pics associated with Irfanview. Every now and then, its resets to Windows Picture and Fax Viewer. Does anybody know why? I have to go back to program defaults and make Irfan View default. Its happened twice in the last 10 days. I've not associated any image files with any other program. Can I lock it to Irfan View? BTW I'm on Win 8 Pro.