If the Excel add-in installed correctly, then it's likely Word was already running when you installed the Word add-in. This is possible if you use Outlook and haven't changed the email editor from its default. Try quitting Outlook and checking Task Manager for any stray winword.exe processes - and kill them if necessary.
The other thing to check is whether the Alfresco toolbar was created at all. Right-click on the toolbar area and see if there's an Alfresco toolbar in the list. You may need to tick the checkbox to make it visible.
CIFS Server is the normal way you access Alfresco over CIFS. This might be a network share, e.g. \\ServerA\Alfresco or a mapped drive like Z:\
Speak to whoever installed your Alfresco server for the correct entry.
Thanks,
Mike