I understand the problem is displaying large images and video content in Fx 11 under windows 7, Sometimes, the video or audio content in a web page cannot be properly downloaded and displayed in Firefox. A required plugin may be missing, outdated, blocked, in conflict with another plugin or extension, or the content may be blocked for some reason. This article will help you solve these problems: [https://support.mozilla.org/kb/Video%20or%20audio%20does%20not%20play video or audio does not play] Do not hesitate to come back and ask for more if this is no help - I am not that well versant in Norwegian (if I got the language correct in the first place;)