You might try F1, F2, F10 or DEL Those are all pretty common. Also you might try to DL the mobo manual. Use a mobo detector software to determine what the make of you bios is. That will be helpful in determining the hot key to enter the bios.
my acer keeps blue screening me and then i struggle to restart it, it keeps erroring, after about 10 mins of trying to restart it it starts but only works rof about 20 mins then blue screen again, any ideas