Com port not found by program

I installed Motorola Phone Tools succesfully, including the motorola modem to connect the phone by USB cable for data synchronization. The device manager shows successful modem installation (Com 5)and the query feature successfully communicates with the attached phone. When I try to use the software, an error message "communication port unavailable" appears. The motorola support says the laptop system does not recognize the com port and it needs to be made available to the software. Help please???