Can't open .pps file from WM

If a get a power point file attachment in the Windows Mail, then I get an error message telling me that the file needs to be associated. I am on Windows Vista and PowerPoint Viewer is already installed on me pc. I have already tried to associate the power point file by downloading it from the attachment and then even after right clicking on it and then checking the box "Always use PowerPoint viewer with this file", still when I try to open it up in Windows Mail, it will give the same error. Can anyone tell me how do I fix this problem. Thanks.

Check the below step by step method on how to solve this issue:

1. First of all you need to click Start and then type regedit.exe and press ENTER
2. After that go to the following path:
3. HKEY_CLASSES_ROOT\PowerPointViewer.SlideShow.11\shell\Show
4. Now yo have to right-click Show and click Rename
5. After that need to type the word Open so that Show is replaced by Open
6. Now, when you have you have PowerPoint Viewer installed, repeat the above steps in this key, as well:
7. HKEY_CLASSES_ROOT \ PowerPointViewer.SlideShow.12 \ shell \ Show
8. Lastly, when you have changed Show to Open, close Registry Editor window.
9. Restart and check now if the problem still persists or not.

You can try one workaround that I found on some other website. You need to first of all right click on the shortcut which you are using to open in Windows Mail and then Select Properties. After that you will come accross a field labeled "Start in" on which you need to change the entered value to %UserProfile% and then click ok. Now you have to restart Windows Mail and then try to open the attachments, it will open properly.