pps files

I cannot open pps files from my email client (windows live mail) and have to save them to my desktop to do it. I have PowerPointViewer 2007 installed and the association is correct.
Also, the current default for my other "pp" files is MS Open XML Converter, and I don't have the option anywhere to change them to PPV. My friend with the same OS has all his "pp"s current defaults set as PPV, which I understand is correct.
Can anyone please help ?

Doen't "Open with" give you the option to browse. (Bottom square)
You can then see where you have the viewer located and select it.

Thank you davehc, but I submitted the query wrongly and mislead you.
I have now edited my question.

I might be wrong, but I think file associations are under Folder Options...does it not allow you to change the association, or Live Mail just isn't playing nice?

Never used Live Mail myself, so it may be specific to that app.