Hi today I'll be showing you how to change your default PDF viewer in Mozilla Firefox the PDF viewer that your browser uses will affect how PDF files that you want to open through the Internet will look like and how they function sometimes using your browser's native PDF viewer instead of a more traditional program like Adobe Reader can cause certain PDF files to not open you may be presented with a page that says please update your version of Adobe Reader in order to view this file this actually may not have anything to do with your version of Adobe Reader because it's actually your browser's PDF viewer that is trying to open it and not Adobe Reader so let me show you how to change your browser's PDF viewer well go ahead and double-click to open Mozilla Firefox and the first thing I want to do is actually show you what a PDF opening and Firefox is native PDF viewer looks like so in this Google search bar I would just type in sample PDF and I'll go to the first result which are some sample test questions for an AC t-test and so once it loads I'll see that this is not Adobe Reader it looks quite different I have a different looking tool bar here most of the functions that would want are present but it is definitely a different piece of software and so this is how Firefox previews PDFs itself and this will be your default option if you have not changed anything so now let me hit the back button just to go back to the search results now I will open up the menu in Firefox by clicking on the three parallel lines in the right corner and then everyone should have an options button it might be in a different spot for you depending on how you've organized things but once you open the options you want to go and enter the application section you might be in the general tab initially but go ahead and open applications not at the very top but a little ways down in the content-type column you should see Portable Document format and now we will change the action that occurs so by default you have preview in Firefox if we open up this drop-down list we're actually presented with several different ways to take action on this document type so we can move away from preview in Firefox and actually have it ask us every time this could become a hassle every time you want to open a PDF so let's actually see what Adobe Acrobat in Firefox will look like so we'll choose that option and click OK and now I will reopen that same PDF now I actually see that Firefox is blocking Adobe Acrobat which is now the PDF viewer so I have to activate it here and I can say go ahead and remember that so.