Computer wont restart! help!!!?

I went on firefox,yahoo,facebook,then I went to click 'home' and it started to download the home icon...then i tried to click other icons on firefox and they do the same thing. So I restarted the computer, now it wont restart. I tried to take out the battery, take out the charger, then press the power button for 30 seconds, then plug in the charger, followed by the battery then turned it on. And that helped me get the computer back on for a sec, but i went on firefox again and it wouldn't let me click on anything, just downloading it. So i tried to restart and take out the battery and all again and now it wont come back on at all. what do I do??