If the program you're importing the presentation from doesn't support .wmf or .pct files, save the slides in a graphics file format that's built into PowerPoint or for which a graphics import filter is installed.
Converting a presentation using text file formats
To save the text portion of a file in a format PowerPoint can open, save it as a Rich Text Format (.rtf) file. If you don't want to save text formatting, or if your program doesn't support .rtf, you can save the presentation as a plain text (.txt) file.