Originally Posted by WordTips

When Word calculates line width and wraps text to the next line, it tries to break the line at either a space or a hyphen. Sometimes, however, you may not want Word to break a line at a certain space. For instance, you may want to make sure that two adjacent words appear on the same line as each other. The answer is to use non-breaking spaces instead of regular spaces when you don't want Word to break a line at a certain space. To do this, hold down the Ctrl and Shift keys as you press the Spacebar. Word will then not break the line at that point.