Acer – Aspire, Power, Veriton, Extensa, Ferrari, TravelMate, Altos
• Press Del or F2 immediately after powering on.
• 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 to access BIOS.

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, 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 to enter BIOS.
• 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 screen.
• Other eMachine computers may use F2 to enter BIOS.

Fujitsu – LifeBook, Esprimo, Amilo, Tablet, DeskPower
• Press F2 once the Fujitsu logo appears.

Gateway – DX, FX, One, GM, GT, GX, Profile, Astro
• Press the F1 key repeatedly after restarting the computer.
• Some older Gateway computers use F2 to access the BIOS Setup utility.

Hewlett-Packard (HP) – Pavilion, TouchSmart, Vectra, OmniBook, Tablet
• 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.

IBM – PC, XT, AT
• Press F1 immediately after powering on the computer.
• Older IBM computers (including some laptops) may utilize the F2 key for BIOS entry.

Lenovo (formerly IBM) – ThinkPad, IdeaPad, 3000 Series, ThinkCentre, ThinkStation
• Press F1 or F2 after powering on the computer.
• Older Lenovo products allow access to BIOS 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 to enter BIOS.

Sharp – Notebook Laptops, Actius UltraLite
• Press F2 after the computer starts.
• Some very old Sharp PCs require a Setup Diagnostics Disk to access BIOS.

Shuttle – Glamor G-Series, D’vo, Prima P2-Series, Workstation, X Mini 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.

The following companies are either closed for business or no longer manufacture or support mainstream computers systems so verifying the following BIOS access information is nearly impossible. I have included what I could dig up for anyone who might be interested:

ARI / ALR / AST (Advantage) – Press the Ctrl+Alt+Esc or Ctrl+Alt+Del keys.

Cybermax – Press the Esc key.

Tandon – Press the Ctrl+Shift+Esc keys.