How do I make Yahoo the default mail system?

Factual Questions
1

This is for a friend, so I’m giving the info I know and will get more if needed.

He’s using XP with IE8. If he wants to right-click and “send to” it gives either Outlook Express or Hotmail. He wants it to be Yahoo. On his tower it’s set that way but not on the laptop. It used to be set that way on the laptop, but he doesn’t know what he did to change it.

Any of this make sense? Any advice?

Thanks in advance.

2

This is one of those questions where Google is more helpful (and faster) than the Dope: Help for your Yahoo Account