Every now and again somebody sends me a Powerpoint presentation full of images which have been replaced with a big red X in a box. The reason is simple: they cut the graphic in one application and pasted it into Powerpoint on a Windows machine. Sorry to say this often creates a file that will only read properly on other Windows machines. Those of us with Macs are in trouble-and you might be too if you have to present your talk using somebody else's machine.
A far better approach is to export or save the image as a jpg from the program that created, then import it into Powerpoint. The command path for this is: Insert -> Picture -> From File which will then let you navigate to the image and place it in the slide.
Powerpoint has gotten a lot better about supporting other file formats over the years. That said, if your goal is a (relatively) painless transfer of a drawing you did in Powerpoint to, say, Illustrator, the most reliable way is to print it to disk, then use Acrobat to turn the resulting Postscript file to a PDF, then open the PDF with Illustrator. Of all the variations, this one seems to be most reliable.
All images and text Copyright Dale Austin, 1962-2008