To access bios in generally depend on that motherboard manufacturer company. Different comany different types of shortcut to open bios in that mothe board.
Here I write some shortcut key to open BIOS.
Acer - Press F2 or Del
Compaq - F10
Compaq Presario - Press Alt+Ctrl+Esc
Cybermax: Press Esc Key
Dell - F1 or Del.
HP – F1
Hewlett-Parkard (HP) Tablet PC: Press F10 or F12
IBM PS/1 (Late Models), PS/ValuePoint and 330s: Press Ctrl+Alt+?
Sony - F3, then F2, or F1
Sony Vaio 320 Series: Press F2
Toshiba Laptops - Press Esc Key.