Microsoft Word 2003, by default, uses your operating system’s default unit of measurement. If, however, you would rather the ruler use centimeters instead of inches, or vice-versa, do the following:
1. Choose “Tools” then “Options”.
2. When the “Options” multi-tabbed dialog box appears, click the “General” tab.
3. Next to the “Measurement units” pull-down, choose your desired unit of measurement, such as Inches, Centimeters, Millimeters, Points, or Picas.
4. Press “OK” to close the dialog box.