I cannot send a fax using PC-FAX (Windows 10)

I'm using Voice Over Internet Protocol (VoIP) and am having problems sending faxes. 

The rainbow cursor keeps spinning when I click on Copy/PC-FAX in ControlCenter2 (For Mac OS X 10.7).

When I send a fax from the machine, an error "not register." or "not registered." is displayed.

I'm using Windows 2000 and Windows XP. I want to use a name from my address book to send a FAX. The address book is stored on a network share and when I try to access the address book I can not open it.