Creating a quality presentation that is error free and easy to read is a natural objective when you use PowerPoint, and PowerPoint's spelling and style checkers can offer some assistance in this area. Keep in mind that, although these automated tools can help you catch errors, they aren't foolproof and don't take the place of thorough proofreading by a real person. To set options for spelling and style checks, select Tools, Options and go to the Spelling and Style tab. Figure 3.12 illustrates this tab.
You can choose any of the following spelling options:
Check Spelling as You Type Underlines each suspected spelling error as you type it.
Hide All Spelling Errors Doesn't display red underlining for suspected spelling ...