When a user tried to open a PDF Document via Adobe Reader X after an Adobe Reader Update it produced the following error message “Before proceeding you must first launch Adobe Acrobat and accept the End User License Agreement” I thought this related to the End User License Agreement of Adobe Reader , so I tried to open it standalone but it did not bring the terms and conditions. The machine previously had Adobe Acrobat 8.0 Installed as a trial , but this was unistalled so Adobe Acrobat 6.0 Licensed copy could be installed. I tried to open adobe acrobat 6.0 however there was no End User License Agreement either. It looks like Adobe leaves some old registry information , so a complete unistall of Adobe Products on the machine and reinstall should fix the problem. However an easy fix, is to open up Adobe Ready , Go to Edit / Preferences / General Then tick the box to “Enable Protected Mode”