Change pps to ppt

I receive powerpoint slideshows in emails as attachments and attempt to change the pps to ppt to edit them, but am unable to change the extension.

A much safer way to do this is to open PowerPoint
File > Open navigate to and open the pps and then save as a .ppt

Alternatively right click the .pps icon and > New

Changing the extension no longer works in 2007 and even in earlier versions you can make mistakes easily if you are not sure what you are doing!

Thanks very much for answering my question. I saved a pps file to my hardrive, then renamed the file .ppt. That did it. Thanks