cant get passed the acer symbol or into the bios menu please help

[ken gavrailoff]

hi i have a acer aspire one 725 and I need get into bios menu u see my problem is my nephew was using my netbook and when I went to go on it I was asked for a bios password and he cant remember what he did can someone please help im trying to install a new harddrive but need to get into bios menu