No more connections can be made to this remote computer at this time because there are already as many connections as the computer can accept.
This message occurs if the computer reaches the maximum number of inbound connections that the computer can host.
For Windows XP Professional, the maximum number of other computers that are permitted to simultaneously connect over the network is ten.
This limit includes all transports and resource sharing protocols combined. For Windows XP Home Edition, the maximum number of other computers that are permitted to simultaneously connect over the network is five. This limit is the number of simultaneous sessions from other computers the system is permitted to host. This limit does not apply to the use of administrative tools that attach from a remote computer.
For more information please see the following link.