Symptoms
'Duplicate Name On the Network' Error
Cause
Someone else may be using the same name on their computer.
Resolution
1) Go to Properties on the network neighborhood, click on Identification tab, change the name or add a number at the end of name on the computer.
2) Reboot. If you had a computer before and passed it on to someone else, it probably will have the same name. You can go to that computer and change the name on it, the same way as above.
OUTCOME
Warning no longer appears and you will have unique name on the network.