Q: Sometimes when I try to open a file or e-mail I get the message: "The selected file has an extension (PDF) that is not recognized by Windows Media Player but the player may be able to play it.

The Portable Document Format makes it possible for you to open and view documents, no matter what operating system, software or computer you have. To make this happen in Yahoo Mail, the email program ...

Adobe's portable document format (PDF) has become a standard for exchanging and distributing documents. PDF files look like the original document would look if it were printed, and can be read on just ...