Hello Heather

Have a look at this web page which tells you how to set up an outlook express account from scratch. Just follow the instuctions and you should be ok. I had that annoying "enter password" box a few years ago and the problem was that I had the @ sign in the incoming mail server account name. It's just something as simple as that.
You can have a look here to check your settings. It displays screen shots to make it easy to follow. Follow the links at the bottom of each page to take you through the set up.

Have fun.