Guides in PowerPoint 2010 are not visible by default, and you have to manually make the guides visible on the PowerPoint slide. When the guides are made visible on any slide, they show up in the same position on all other slides within the http://www.blogger.com/img/blank.gifpresentation. You’ll find that only two guides — one horizontal and one vertical guide are visible at first, and these two guides intersect at the center of the slide. Most of the time, this might work for you, but you can actually add more guides since these can help in positioning slide objects better across successive slides.
Learn how to add more guides in PowerPoint 2010 for Windows.

