Cannot log in to Windows Live Mail

I want to use the Windows Live Mail program to work within multiple email accounts (2). When I try to sign in to Windows Live Mail program on my computer, the prompt says my email or password are incorrect. They are both correct, so I'm completely frustrated. I have changed the password several times, in order to make sure it's not that I'm forgetting my password, but I still get the error message "The email address or password is incorrect. Please try again." I have tried everything... and am about to lose patience. Please help. Thank you.