By default PowerPoint presentations saved in PowerPoint 2003 are saved using the presentation file format that is compatible with PowerPoint 2002 and 2000. If you are upgrading from a version of PowerPoint that precedes PowerPoint 2000, you should be aware of some file compatibility issues.
For example, when you open a PowerPoint presentation saved in PowerPoint 97 or 95, the presentation will be upgraded as it is loaded by PowerPoint 2003. You can then save the presentation in the newer presentation file format (the standard for PowerPoint 2000, 2002, and 2003). If you are planning on editing or playing a presentation on a computer that is running a pre-2000 version of PowerPoint, you can save the presentation in a legacy file format ("legacy" simply means an older file format).
To save presentations in a pre-2000 file format, follow these steps: