PPTViewer 2003

[mexy]

Hi,
I need to launch a PPT file on a "Internet Explorer" browser; I Installed
PPTViewer 2003, but I realized that a popup appears to ask me if I want to
open or save the file.
I tried with PPTViewer 1997 and it was OK! There wasn't any popup.

I would like to try again with PPTViewer 2003 and so I unistalled
PPTViewer 1997 and I reinstalled PPTViewer 2003.
Now it happens that it doesn't recognize pps files any more and the popup
show me only the save button and the abort one.
What's the matter?
Is there any key to delete in the configuration registry?

Thanks.