I ussaully keep my computer on 24/7 but today I turned it off for a couple of hours, turned it back on and received this error: lsass.exe - System error Object Name not found. this comes up on a black background as it is supposed to be loading the login window, followed by a reboot as you click the OK button, it then happens again..... I use Win XP Pro. Do I need to re-install Windows???