file association for .pps does not work

I have Microsoft Power point and in the association list, power point is designated as the software to be used for .pps files. When I get a power point downloaded attachment to my email client (.pps) and I click on it, I get the message that "it could not be opened because the helper location could not be found". I'd like to get this to work. I do know that I can save the attachment, open power point and view it but merely clikcking on it should work. Any suggestions?

I think that's a problem with how your email client is set up, not with Windows' file associations.
Your email software should allow you to edit what it does with attachments you try to open - basically it maintains a list of its own file associations.

I'm using Thunderbird and I don't know of any file association list.

I found the association list under tools and the .pps file extension was associated with power point. I did change the action to "always ask" and then when I cloicked on .pps file in an email attachment, it asked me to select the software and then I clicked on always use this app. Now it works. Thank you very much because I didn't know that the email clients had their own association list.

Glad you got it sorted out! I used Thunderbird myself a long time ago until I saw the light of Gmail, so I remembered those separate associations. BTW, every browser including Firefox has the same thing. :)

No, it doesn't necessarily have anything to do with email. Firefox for example just tracks what to do with a given filetype (just download and save it, show/play it in the browser window if plugins are available to handle it, or download to the FF cache and open with an external program).