computer worked great this morn with no prob. this after noon tryed to boot and it is stuck in a boot looop after windows progress bar. tryed f8 safe mode did not work. reset boot up to cd for windows cd repair does not work. tried cmos to safe set up does not work. came up with were sorry screen and to click on safe mode of last good config but it wont let me arrow up. running out of things to do. please help.