Error 38

I have 15 computers on an office network, I have one
computer that I am trying to change the computer name. I
right click my network places, go to indentification,
change the name. Every time I reboot I get an error
message 38. Have tried several different names, same
result each time. I only have this problem on one
computer. Does anyone have any suggestions? The error says
that I already have a computer with the same name. I have
tried names that I know are not being used. Many thank!