I fell asleep playing games on my acer aspire v5-571p lapton charging couple nights.. it happened again yesterday n i woke in d morning n plugged it out n put it to sleep mode..came home from work n turned it on with charged plugged in n was playing games.. then bout 2 hours later it says battery is 7% n the charger was plugged in all this time.. anyway the laptop charging light is there but not charging.. laptop dies and wont power back on..d charging light wont come on d laptop either.. i removed d battery n pressed d power buttton for 20 seconds n then put back d battery n it came up.. but i didnt see d boot function keys selection screen..only message came up was 'operating system not found'.. what is wrong?