There are hundreds of computer manufacturers out there and each seems to have their own idea when it comes to designating a key sequence to enter BIOS. There are often even huge differences in access methods between different models made by the same company!
Acer
Aspire, Predator, Spin, Swift, Extensa, Ferrari, Power, Altos, TravelMate, Veriton
Press Del or F2 immediately after powering on.The Acer Veriton L480G uses F12.The BIOS on the Acer Altos 600 server uses the Ctrl+Alt+Esc key and the F1 key for advanced options.Older Acer computers may use also use the F1 or Ctrl+Alt+Esc keys.
Asus
B-Series, ROG-Series, Q-Series, VivoBook, Zen AiO, ZenBook
Press (or press and hold) F2 until you see the BIOS screen. You may need to press the key repeatedly until the utility appears. Some Asus laptops require that the Del, Esc, or F10 key be pressed instead. Older Asus computers might boot to the BIOS setup utility only if you hold down the Esc key until you reach the Boot Device Selection screen; continue by selecting Enter Setup from the menu.
Compaq
Presario, Prolinea, Deskpro, Systempro, Portable
Press F10 while the cursor in the top right corner of the screen is blinking.Older Compaq computers may use the F1, F2, F10, or Del key to give access to BIOS.
Dell
XPS, Dimension, Inspiron, Latitude, OptiPlex, Precision, Alienware, Vostro
Press F2 when the Dell logo appears. Press every few seconds until the message Entering Setup appears.Older Dell desktops and laptops may instead use Ctrl+Alt+Enter or Del.Older Dell laptops may use Fn+Esc or Fn+F1.
eMachines
eMonster, eTower, eOne, S-Series, T-Series
Press Tab or Del while the eMachine logo displays on the screen.Other eMachine computers may use F2.
EVGA
SC17, SC15
Press Del repeatedly while the EVGA laptop is booting.
Fujitsu
LifeBook, Esprimo, Amilo, Tablet, DeskPower, Celsius
Press F2 once the Fujitsu logo appears.
Gateway
DX, FX, LT, NV, NE, One, GM, GT, GX, SX, Profile, Astro
Press the F1 or F2 key repeatedly after restarting the Gateway computer to access the setup utility. You might have to press and hold the key.
Hewlett-Packard (HP)
Pavilion, EliteBook, ProBook, Pro, OMEN, ENVY, TouchSmart, Vectra, OmniBook, Tablet, Stream, ZBook
Press the F1, F10, or F11 key after restarting the computer.HP Tablet PCs may use F10 or F12.Other HP computers may allow access to BIOS using the F2 or Esc keys.Still others might require that you press the Esc key and then F10.
IBM
PC, XT, AT
Press F1 immediately after powering on the computer.Older IBM computers (including some laptops) may utilize the F2 key.
Lenovo (formerly IBM)
ThinkPad, IdeaPad, Yoga, Legion, H535, 3000 Series, N Series, ThinkCentre, ThinkStation
Press F1 or F2 after powering on the computer.Some Lenovo products have a small Novo button on the side (next to the power button) that you can press (you might have to press and hold) to enter the BIOS setup utility. You might have to then enter BIOS Setup once that screen is displayed.Press F12.Older Lenovo products allow access using Ctrl+Alt+F3, Ctrl+Alt+Ins, or Fn+F1.
Micron (MPC Computers)
ClientPro, TransPort
Press F1, F2 or Del immediately after powering on the PC.
NEC
PowerMate, Versa, W-Series
Press F2 to enter the BIOS Setup.
Packard Bell
8900 Series, 9000 Series, Pulsar, Platinum, EasyNote, imedia, iextreme
Press F1, F2, or Del.
Samsung
Odyssey, Notebook 5/7/9, ArtPC PULSE, Series ‘x’ laptops
Press F2 to start the BIOS setup utility. You might need to press this key repeatedly until the correct screen appears.
Sharp
Notebook Laptops, Actius UltraLite
Press F2 after the computer starts.Some very old Sharp PCs require a Setup Diagnostics Disk.
Shuttle
Glamor G-Series, D’vo, Prima P2-Series, Workstation, XPC, Surveillance
Press F2 or Del on startup.
Sony
VAIO, PCG-Series, VGN-Series
Press F1, F2 or F3 after turning on the computer.
Toshiba
Portégé, Satellite, Tecra, Equium
Press F1 or Esc after powering on to access BIOS.Press F12 on a Toshiba Equium.