You are attempting to open a file type that is blocked by your registry policy setting in Power Point

Information about certain file types that are blocked after you install Office 2003 Service Pack 3.
After you install Office 2003 SP3, the following Microsoft Office Excel 2003 file types, Microsoft Office PowerPoint 2003 file types, and Microsoft Office Word 2003 file types are blocked. By default, these file types are blocked because the parsing code that Office 2003 uses to open and save the file types is less secure. Therefore, opening and saving these file types may pose a risk to you.
  • Double-click the file that you saved in step 1.
  • Click Yes to confirm the installation of the file.
  • If an Office program is running, restart the Office program.