I get an error on machines on our work network that says Adobe Reader/Acrobat is not installed. However most cases it is installed on the machine and in most cases it turns out to be the 8.1.1 version of Adobe reader. So what we have noticed is that the permissions do not seem to be right with the .pdf file extention. We manually add the users, power users group to the file extention and then we grant them full control over the extention and in most cases that as well will not work. The next step would be to uninstall 8.1.1 Adobe reader and then reboot. Upon the restart we will log on and install the 8.1.2 update. Sometimes this works but then again I have noticed that the users, power users group is not in the .pdf file extention. Then we will add them in and yet the user will still have the same error message. We have fun out of ideas and the other bad scenario is that this is free software and its very difficult to get support for. Anyone have any ideas?