Acer Aspire freeze on acer logo

hi anybody , i dont know what happen but my laptop can past the acer logo when booting , its some kind like freeze , i press F2 F10 esc F8 , its not response , try remove hdd clean ram remove and plug in the cmos battery , nothing happens it still freeze like before , any ideas please ? im going stressed because this problem , i need my laptop for do my work .
thankyou btw i use acer aspire 4755G , windows 8.1 before freeze