SYMPTOMS
When you open a presentation created in an earlier version of Microsoft
PowerPoint, make some changes to the file, and then attempt to save it, you may
receive the following error message:
The file <Filename>.ppt is currently a PowerPoint <Version Number>
Presentation. If you made changes to your PowerPoint presentation using
new PowerPoint 98 features, the changes might not be saved to an earlier
format. Do you want to overwrite it with PowerPoint 98 format?
If you click Yes, PowerPoint 98 overwrites the original file with the newer
formatting. If you click No, PowerPoint 98 saves in the file in the original
format, removing those features unique to PowerPoint 98.