Can't login into WLM or Msn

Problem description: I can’t login into WLM or Msn, I was on-line yesterday at night, but today I got this error. What can be the problem?

Error code/error message: (Wrong password) error 80048821

What has been tried so far: I unchecked ‘‘remember account & password’’, some configurations in internet explorer, reinstalled the program several times and fixed date and time, but nothing happens. I don’t know what more can I do…

Messenger version: 7.5; 8

Windows version: 7