One of our customer got a problem with their CRM program after upgrading to Office 2013 and then downgrading to Office 2010. A button to open the Outlook client doesn’t work anymore.
When I use Sysinternals Process Monitor I can see that the program successfully locate the default mail client. But It tries to open wrong registry key. It should use 14.0 but use 15.0 instead. Does anyone know how to remove all references to the 2013 version of Outlook (15.0)? And yes I uninstalled Office 2013 before installing 2010.
See attached image.