Many LANs are setup where there is no user name but 
a machine name (i.e., frontdesk).  If you want to change
this to your name or a user name, all you need to do is
use the SETNAME command.  Simply

type SETNAME followed by a name and you can log in 
with any name you choose.

For example,

SETNAME TOM

will change the NETTALK name to TOM.

You can also put this in your autoexec.bat for permanent
changes.

Hope this helps.