if you cant get it to open in safe mode, i.e. you werent fast enough to press the button, hard start your computer,(shut it off the hard way, if you have a desktop, unplug it while its running.) it will give you the option of starting in safe mode when you restart it. thats also a convienient way to get into an administrator account in school, but i wouldnt know anything about that. computer classes can get so boring sometimes.