.prn

File created by choosing "Print to File" within the Print dialog box; contains text and other content to be printed as well as instructions for the printer, such as number of pages to print and what printer tray to use; similar to a PostScript (.PS) file.

PRN files may be printed in Mac OS X by dragging the file to the desktop printer icon. In Windows, they can be printed by right-clicking the file and selecting "Microsoft Office Document Imaging" (only some versions of Microsoft Office Document Imaging support PRN files). You may also open them via the Windows command line. To do this, select "Run" from the Start Menu, type "cmd," and perform the following steps:

If the printer is connected via USB, type:
"COPY /B [filename.prn] \\[Computer Name]\[Shared Printer Name]"

If the printer is connected via an older parallel port connection, type:
"COPY /B [filename.prn] LPT1:"

Important: Do not include the [brackets] when typing the actual command.