A port with that name already exists, Choose another port name.

Open Printer and Faxes
Go in File Menu and Choose Server Properties

and Click on PORT Tab Menu
now Select You Port Number
And Click On Delete Options
Click on Yes and Apply

Close all Windows and Try Again

If this Method is Not Working Properly Then Choose 2nd Method

2nd Method

http://deepuinfo.blogspot.com/2009/11/port-with-that-name-already-exists.html