Abstract: A computer system running a Windows™ operating system is capable of remote printing on a printing system remotely connected to the computer system over a network in which the transmission of the print data over the network is secure. The computer system has a print-source program which generates print data for printing a document. The local print provider of the Windows™ operating system has a port monitor which transmits the print data to the printing system over the network using a secure transmission protocol in which the transmitted data is encrypted. The printing system, which comprises a printer device capable of printing, has a server program capable of decrypting the print data received from the computer system using said secure transmission protocol, and a printer program capable of controlling the printer device using the print data to print the document.