Please be more specific about what software you are using. Word 2000, 2003, 2007, etc?
- Bullets and Numbering…
- List Styles (list styles allow 1.1, 1.1.1, etc.)
- By default, the second available option of lists should be the one you want.
- In your document, if the headings appear as the same number, right click the headings in the order they appear, and select Continue Numbering.
To separate chapters or headings, try using a Page Break, so that formatting numbers and bullets is easier.