As per the description above, you are not able to open any PDF file in Outlook or on your desktop, Is that correct?
Assuming the Adobe Reader is installed, Open Reader, navigate to Edit menu -> Preferences -> Security Enhances & disable the Protected mode.
Check if it brings any change.
If this does not help, you may try to uninstall Reader using the cleaner tool: Download Adobe Reader and Acrobat Cleaner Tool - Adobe Labs Link: http://labs.adobe.com/downloads/acrobatcleaner.html
Hope this helps, and keep us posted with the results.
Thank you for your feedback, I unfortunately cannot open Adobe at all except in a browser and therefore am not able to access the Menu, I am so desperate. I have used the cleaner and uninstalled and reinstalled so many times I cannot even remember. I do believe that the solution may be in the menu, preferences and security enhances but I cannot access it.
Hi again Anand Sri
Thank you!!! it worked, I have also gone in and disabled the protected mode under Security Enhanced and (disabled) the Enabled Protected Mode at Startup.
Thanks again, I was losing hope.
hi Anand Sri
I am having to do this once a week as that is how often my pdf's won't open. The link you sent me works, but only for a while and then I'm back to square one again without pdf's.
Please can you assist.
Sorry for the delay in response to your query. Please try to delete the preferences of Adobe Reader and check. To delete the preferences refer to How to reset Acrobat Preference settings to default.
Let us know how it goes.