New install of Windows 7 OEM with Office Pro 2013. When browsing the folders in Windows explorer, with the preview pane on, saved email messages do not preview and instead show a warning that says "Microsoft Office Outlook. Either there is no default mail client or the current mail client cannot fulfill the messaging request. Please run Microsoft Outlook and set it as the default mail client."
Outlook is set as the default mail client. Other files can be previewed on the same machine - PDF, XLS, DOC, JPG, etc. but not email. The exact same email file (located on a shared server folder) can be previewed on other machines on the network.
The files open okay but give this error message each time. (See photo)