GIF Image Problem

[Richard]

I have a number of PowerPoint presentations with GIF
images inserted in them. They were fine. Today, when I
opened a presentation to work on it, the GIF images are
not visible on the slides, and I receive a message in
PowerPoint that the application is not supported on the
computer. Strange I thought. It was supported yesterday.

I e-mailed the Presentation to another computer and
opened it and, sure enough, the GIF images were visible
in the presentation. Does this mean that I must delete
and re-install Office again on my computer?