If you have the latest version of Microsoft Powerpoint you will have noticed that by default your presentations have a new file extension of .pptx
Older versions of Powerpoint (circa 97 - 2004) can't read this format without an additional piece of software from Microsoft to handle the conversion.
So if you don't know what version a colleague has installed it might just be easier to save the presentation as the older .ppt format..
Below are screenshots of the Save As feature within Microsoft Powerpoint 2011 for Mac and Microsoft Powerpoint 2010 for Windows.
