windows vista home premium, can't log in . . (OS)

To those pro out there .. ..my friend notebook hp pavilion dv3. .windows vista home premium. .suddenlly when he turn on the notebook. .he just can't log on to the windows . .in main screen . .using password also cannot . .and thumb print also. .can anybody help him out of this . .
. .he remember last thing when shout down is upgrade his msn massages. .nothing else. .please help
{links removed}