Create lists with AutoFormat or turn it off

Do one of the following:

• At the beginning of a paragraph, type a number, a separator, and then a space or tab. For example, type 1. and then a space or press Tab. Word automatically changes the paragraph into part of a numbered list:
  
• At the beginning of a paragraph, type an asterisk (*) and a space or tab. Word automatically changes the asterisk to a bullet and applies a hanging indent to the paragraph. You can also type a hyphen (-) and a tab at the beginning of a paragraph to create a "bulleted" list that uses hyphens as the bullets:
  

You can turn off AutoFormat creation of numbered and bulleted lists. Follow these steps:

   1.   On the File tab, click the Options button:

   2.   Choose the Proofing tab, and then click the AutoCorrect Options... button:

   3.   In the AutoCorrect dialog box, choose the AutoFormat As You Type tab, clear the Automatic bulleted lists check box and the Automatic numbered lists check box:

See also this tip in French: Comment créer des listes avec Options de correction automatique ou l'éteindre.