Saving Your Mac Keynote File for Microsoft PowerPoint
To save your presentation into the PowerPoint format, open the presentation in Keynote. Click on the "Share" menu, then click "Export" to view a dialog that provides options for exporting as a PPT (PowerPoint Presentation), PDF, image, HTML or iPod compatible file. Click on the "PPT" option to view a wizard that walks you through the exporting process.The wizard is relatively simple and involves choosing a name for the exported file.
Click "Next," then type a name for the presentation and select the target location in the "Save As" dialog box that appears. Click "Export" to convert the file and save it to the chosen location. After the process completes, Keynote displays a dialog letting you know of any problems that occurred in the process. For example, there may be a slight difference in how certain fonts appear in the converted document. This would mainly be a problem if you use special fonts on Mac that are not compatible with PC. If something major goes wrong, the notification offers resolutions such as changing the problematic font. In most cases, however, this should not cause a major problem.
Although this exporting process will likely suit most users, Keynote also offers you to send a converted document via email. This can save time since you don't have to worry about attaching the converted document manually. If you want to email a presentation in the PowerPoint format, select "Send via Mail" followed by "PowerPoint" on the "Share" menu. Mac Mail will launch, and a new message with the attached presentation will appear.