I have followed the instructions on installing the GTM plug-in but it does not work. It is added into the Add-ins but does not give me the ability to create a meeting in the calendar view. There is also no "Meeting" button added to the Outlook ribbon. When I checked the plug-ins on Outlook, GTM is the only disabled with no way of enabling it. I have tried uninstalling it and reinstalling it with no success.
What version of Windows and Outlook are you using? Does Outlook say why the plug-in is disabled?