If you use the Normal style in Microsoft Word 2007 or 2010, by default this is set as double spacing every time the Enter key is pressed. If you would like to go to the next line when you press the Enter key you can change the default paragraph spacing.
Open Microsoft Word. On the Home tab, in the Paragraph group, click the Quick Launch dialog box arrow. The Paragraph dialog box is displayed.
In the Spacing section, select the required Before and After paragraph spacing. Click Default.
You will receive a warning message that you are changing the Normal template. Provided you are happy to do this, click Yes.