Microsoft's viewer for PowerPoint files uses a proprietary technology that only works in IE. What should happen in Firefox is that you get the Open/Save/Cancel dialog. Do you get that?

Thank you very much for your answer. I didn't get anything from firefox. I understand that PP works with Microsoft technology but in the past it was working and sometimes it works with firefox...Thank you.

Perhaps if you change your setting here:

orange Firefox button or Tools menu > Options > Applications tab

In the search box, type power and then pause until the list is filtered. If you have these, try changing the action to "Always Ask":

Microsoft PowerPoint Presentation
Microsoft PowerPoint Slide Show

It's possible that if you don't have Microsoft Office installed, you might not have those listed.

I get that, but when I click open, it does nothing.

so, nothing came up when I searched power, so I don't have it installed, is there a download from mozilla that I can get so .pps will open?

You can download and install a PowerPoint viewer if you do not have one.

• http://www.microsoft.com/download/en/details.aspx?id=13 Download: PowerPoint Viewer

Thanks cor-el, it was a long download at my speed, 60meg file, but it works and I thank you!

You're welcome