My laptop is an Acer Aspire E 15, and I think I may have overwhelmed it by opening too many tabs on Google chrome (12 tabs in total). The laptop doesn't feel that hot, though. No key I press makes any difference, and touching the touchpad doesn't move the mouse. The laptop doesn't shut down when I close it or press power. I had some music playing before it froze, and now the laptop is making a strange electric humming noise that sounds like the last note of the music being repeated. What can I do? It's been 22 minutes since it froze.