This behavior occurs if the computer reaches the maximum number of inbound connections that the computer can host. Any file, print, named pipe, or mail slot session that does not have any activity is automatically disconnected after the AutoDisconnect time has expired; the default for the AutoDisconnect time is 15 minutes. When the session is disconnected, one of the ten connections becomes available so that another user can connect to the Windows XP system. You can configure the AutoDisconnect time by running the following command from a command prompt:
Here time is specified in minutes.
net config server /autodisconnect:time_before_autodisconnect