Mac MVP James Gordon has posted directions on how to convert old (.ppt) files to standard (.pptx) files using an Automator workflow.
What does this converter do?
You choose one (.ppt) file, several (.ppt) files, or an entire folder filled with (.ppt) files and the converter will save a copy of each PowerPoint file in standard open XML file format, better known as the “new” (actually more than 5 years old now) PowerPoint (.pptx) format. . . .
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