Depending what file extension the attachment is your Windows needs an application associated with that file type.
For example a .pps file needs Microsoft's PowerPoint. There is a free PowerPoint viewer available here;
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=048dc840-14e1-467d-8dca-19d2a8fd7485&displaylang=en&pf=true
However if you already have Microsoft Office installed and it includes PowerPoint, then try this. Save the attachment to your hard disk, then run it from there.
All attachments need the proper application. We can't tell you which ones because we don't know what attachments you get.
But I hope that helps.
Mark
I am using Windows 7 and Windows Live Mail. When someone sends me an email with an attachment some of them I can NOT open. When trying to open the attachments with different file extension ( such as .pps) they will not open. They bring up a window of choices to use but how do you now which one of the choices you are suppose to use??

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