Adobe Reader X – Red X with Internet Explorer on Windows 7

August 15, 2011 by Jeff Gibeau Leave a reply »

I came across this issue recently while trying to install the latest version of Adobe Reader X (10.1).  Once Adobe Reader X was installed, I was unable to view embedded PDF documents in Internet Explorer 8 on Windows 7 x64.  I did a little research and found out that Adobe Reader is 32-bit only, so you are supposed to use Internet Explorer 8 32-bit.  No problem.  I switched over, but to my avail, I was still unable to view embedded PDF documents.  A little red x would show up in their place, meaning the Active X plugin had failed.

I checked the DLLs loaded into the IE process and noticed that only AcroIEHelper and AcroIEHelperShim files had loaded.  I tested on a working machine and there were a few more Acro dlls loaded including AcroPDF.dll.  I assumed the shim was failing to load the correct DLL.  It turned out I was missing a registry key pointing to the AcroPDF.dll that is required by the plugin.  To fix it, I added the following to my registry (Window 7 x64):



I added the same set of keys in my HKEY_USERS section (same path, but with the user id added between HKEY_USERS and Software).

This fixed the issue on my machine, and it loaded the embedded pdf next time I tried opening one in IE8.


{CA8A9780-280D-11CF-A24D-444553540000} is the Class ID for my installed AcroPDF plugin.  It may be different on your system depending on the version of Reader you have installed.  You should replace it with your Class ID which you can find with the following method:

  • Open IE
  • Go to “Tools”->”Manage Add-ons”
  • Change “Show:” to “Run without permission”
  • Right click on “Adobe PDF Reader”
  • Click “More Information”
  • The information is in Class ID

Hopefully this will help someone.  I know I wasted nearly a day of development time trying to work through this issue.


Leave a Reply