password issue on incoming server


New Email
hello, I have an e-mail account that I've had for years. I've been using outlook express and therefore just click on icon to get e-mail. I've recently purchase a new computer which I now have microsoft outlook installed, however I don't know what my password is for my incoming server on my current setup with outlook express.
How can I determine what this is or can it be reset - as I want to keep this current e-mail address.