For Acrobat reader, I get the following error:
"Acrobat failed to load its Core DLL" - I tried installing, uninstalling, reinstalling, repairing - no difference.
I tried different versions of reader - the most recent, and the oldest available - no difference.
I don't know if this helps - I haven't received any respons from the many similar posts in this forum.
Download, unzip and run the attached registry script; it will disable Protected Mode for Reader XI.
When the core library does not work anymore, Acrobat / Reader can no longer run because the components it depends on do not load.
> Enable the hidden Admin Account on Windows 7 ( Ref : http://www.howtogeek.com/howto/windows-vista/enable-the-hidden-adminis trator-account-on-windows-vista/ )
> Disable all Non-Microsoft Startup Services. (Ref : http://helpx.adobe.com/x-productkb/global/disable-startup-items-servic es-windows.html )
> Disable all the Antivirus softwares temporarily from the computer.
This error is known for conflicting Antivirus softwares like CA, Norton,Mc Afee etc.
> Delete the all the contents in the locations mentioned in the doc :
Note: It's possible that your system doesn't contain all of the files and folders listed in this document. If you do not find a listed file or folder on your system, proceed to the next file or folder on the list.
> Reboot the computer and install Adobe Reader 11 and check
The Adobe team has been working on this issue offline and with many of our customers over phone calls and emails. The investigations have concluded that this break is caused due to the presence of malware on the system. We have been able to see significant success with the use of Kaspersky TDSSKiller tool. Many users on the forums had reported the same and we have also been able to confirm results with some infected machines.
If you are facing this issue, we recommend running the tool on your system. For installation and usage instructions, please refer to “How to disinfect a compromised system” on http://support.kaspersky.com/5350?el=88446
We are continuing investigations and will post an update as soon as we have further details.
Thanks to everyone who posted in and provided details. Given that the cause was an infection, detecting and isolating it without your support would have been near impossible.