If the toolbar isn't displayed in Outlook, please use the repair function of the included helper software. (You can find it in Start > Programs > 1-Click Duplicate for Outlook)
Note: Starting with Outlook 2010 the toolbar is showing in the Outlook tab "Add-Ins".
If that doesn't help and the add-in is registered+active, but the "Add-in" tab still doesn't appear, please check:
File > Options > Customize ribbon > Enable the entry "Add-Ins" on the right