Turn off ScreenTips or change the display : ScreenTips « Introduction « Microsoft Office PowerPoint 2007 Tutorial

1. Microsoft Office PowerPoint 2007 Tutorial
2. Introduction
3. ScreenTips

Click the Office button, click PowerPoint Options

Click Popular, click the ScreenTip Scheme list arrow, 
       click Don't Show Enhanced ScreenTips or Don't Show ScreenTips.

1.4.ScreenTips
	1.4.1.	Turn off ScreenTips or change the display