Two Versions of PowerPoint - How to Ensure One Automatically Opens

[Lynn Q]

Hi there,

I'm sending this for a buddy. He has Office 2003 and Office 2007 installed
on Windows XP. Doing a PowerPoint course that requires he uses PP 2003.
However, when he goes in to open the file he was working on it simply
defaults to PP 2007. How do we tell the computer to use 2003 for now until
the course is complete?

We don't want to remove 2007, just need to have the saved files open
automatically in 2003.

Thanks in advance.

Lynn