Each service corresponds to a corresponding port. For example, as we all know, the port of WWW service is 80, smtp is 25 and ftp is 2 1. These services are started by default in win2000 installation. Individual users are really unnecessary. Closing a port means closing useless services. In the control panel "Administrative Tools" in "Services".

(1) right click "computer"->; "management"->; Services and Applications, double-click Services and set the Spooler to Started.

(2) Click "Start->" in the lower left corner of the computer; "Devices and Printers" to see if there is an icon for your printer. If not, you can browse the solutions provided by Epson's website for processing.

Apply through the system:

After calling to establish a connection with the port, the data sent by the transport layer to the port is received by the corresponding process, and the data sent by the corresponding process to the transport layer is output from the port. In the implementation of TCP/IP protocol, port operation is similar to general I/O operation. A process obtains a port, which is equivalent to obtaining a local unique I/O file, and can access a file descriptor in a general reading and writing way.

Each port has an integer descriptor called port number to distinguish different ports. Because the TCP and UDP protocols of the TCP/IP transport layer are two completely independent software modules, their respective port numbers are also independent of each other. For example, the port number of TCP is 255, and the port number of UDP can also be 255. There is no conflict between them.