Can't access Outlook Express email

I use Outlook Express for email and have run into a problem I haven't been able to fix. Now, seemingly out of the blue, when I open OE I'm asked to put in a user name and password and that has never happened before. The worst part is that the user name and passwords I have tried don't work, I can't access my Outlook Express email. Any suggestions? Obviously I am not that savy about this process so dumb it down please! And thanks!
soullyfter

attach this doc I found

Look at this page as well (http://www.microsoft.com/windows/IE/community/columns/passwords.mspx)