How do I set up a default email provider?

Hey people. I use Windows XP, and for whatever reason my default email provider seems to be Outlook. I never purchased Outlook, so I don’t know how how it became my default provider. I don’t have an email address set up with it either.

Can anyone explain why this is? Also can I set up a email account with Outlook even though I never bought it? If not how can I switch the default email provider of my OS?