From within Outlook

Go into the Evercontact toolbar and then click the "Update" button:

(for Outlook 2007, go to Tools>Evercontact and then click "update".)

If you run into the error message "there is an error with this Windows Installer Package.  A program required for this install to complete could not be run" then you'll need to download Microsoft's tool here and then install using that tool.


From a direct download link

 Download the latest version of the Evercontact add-in for Outlook here.

Once it's downloaded, make sure to close Outlook before installing.