I want to switch back to the former version of Yahoo -- as soon as possible. Attaching a file closes the email I wanted to send.?

Once Yahoo upgrades to a new format you can't get the old one back. They remove it from their server.

You cannot since that version has been thrown away. Yahoo Answers is just a forum where the general public can answer questions. It is NOT Yahoo's offices. This is not a paid-for support forum staffed by professional computer whiz kids. None of us are paid anything to answer you, we do not work for Yahoo, we do it out of the goodness of our hearts. Likewise we cannot access nor even see your computer, also we have no control over what Yahoo do.