PDF does not open in IE

User with Win7 complained PDF did not open in IE, and she got the following error.

I removed Adobe Reader and left the Acrobat alone. Checked IE add-on to make sure all Adobe add-on are enabled. Check the default program associated with PDF. All were good but the user still could not open and got the small black icon on the top left corner of the IE.

Then I found out this good article here, and modified the registry to resolve the issue.

Change Outlook Temp Directory in Registry

Update this key, "HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Security\OutlookSecureTempFolder"