Note that these instructions are for Windows users only.
In order to create PostScript files, you need a PostScript printer driver installed on your computer (although you don't need actually need a PostScript printer). A suitable driver is included on your Windows CD-ROM.
Go to Start > Settings > Printers, then click Add Printer, and add an Apple LaserWriter Plus (or nearest equivalent). When prompted for the location of the printer, state that it is a Local printer, and should print to FILE: (not to LPT1:). If asked whether you want to make this new printer your default, click No.
GhostScript is a freely-available PostScript interpreter. It is used to convert PostScript files so that they can print on a non-PostScript printer. GSView is a graphical user interface (GUI) for Windows that makes using GhostScript a lot friendlier. You must download and install both GhostScript and GSView before proceeding.
Further instructions on downloading and installing GhostScript and GSView can be obtained here.
Run GSview and go to Option > Advanced Configure. Make sure the fonts path in the Ghostscript Options (3rd box down) says this -
-dNOPLATFONTS -sFONTPATH="c:\windows\fonts"
(where the path in quotes is the directory where your TrueType fonts are located; this will usually be "c:\windows\fonts" as above.)
You now have various options:
Instructions by Barbara Griffith from Sibelius help-pages.