Anilrgowda

Computer manufacturer's have specific key(s) or key combinations that you have to press when your PC boots up, in order to enter the BIOS setup and alter your system's settings.

This article contains these key(s) or key combinations that let you enter your BIOS Setup Utility, listed with regard to the computer manufacturer and/or the BIOS version you have. Sometimes there are two or more keys or key combinations that will work, while in other cases models from the same manufacturer have different keys assigned for this function.

If you do not get it right from the first time, this might be due to one of the following reasons:
a. You are pressing the right key(s), but you are not pressing them fast enough or long enough.
b. You need to try a different key or key combination, from the other ones for the same computer or BIOS manufacturer.
c. You have a keyboard with dual-function keys, where you need to press F-Lock in order to have the F keys working. Same possibility might apply in keyboards like these, with other keys as well; e.g. Pause or Insert. Some laptops have an Fn key that works in a way similar to F-Lock. So, before trying a different key combination, please make sure you have your keyboard set correctly for the current one.


I. COMPUTER MANUFACTURERS

Acer Ctrl+Alt+Esc
Acer F2
ALR PC Ctrl+Alt+Esc
ALR PC F2
AST Ctrl+Alt+Esc
Compaq F10 when the cursor is blinking in the upper right corner of the screen
Dell F1
Dell Del
Dell press Reset twice
Dell Ctrl+Alt+Enter (on older models)
Gateway 2000 F1
Hewlett Packard F1
IBM Hold down both mouse buttons during bootup (on older models)
IBM F1 (Aptiva)
IBM Press both mouse buttons repeatedly during bootup (Aptiva)
IBM Ctrl+Alt+Ins after Ctrl+Alt+Del (PS/2)
IBM Ins (PS/2 with reference partition)
IBM Ctrl+Alt+? (some PS/2s, such as 75 and 90)
IBM Ctrl+Ins when pointer at top right of screen (some PS/2s)
IBM Ctrl+Alt+Ins when cursor is in upper-right corner of screen (ThinkPad using IBM BIOS - early models)
IBM Press and hold F1 key while powering-up laptop (ThinkPad using IBM BIOS - later models)
IBM Ctrl+Alt+F11 from DOS prompt (ThinkPad using Phoenix BIOS)
NEC F2
NEC Press and hold F1 key while powering-up laptop (Versa Notebook)
Packard Bell F1
Packard Bell F2
Packard Bell Ctrl+Alt+S
Sharp F2 (Laptop 9020)
Sony F3 while you powering up the PC, then F2 or F1
Tandon Ctrl+Shift+Esc
Toshiba Press Esc during boot, then F1
Toshiba F1 (models using Phoenix BIOS, late model PS/1 Value Point and 330s)
Toshiba Hold down the left shift key during boot (Notebooks)
Olivetti Shift+Ctrl+Alt+NumPadDel (PC Pro)
Zenith Ctrl+Alt+Ins


II. BIOS MANUFACTURERS

AMI BIOS Del
AMI BIOS F1
AMI BIOS F2
Award BIOS Del
Award BIOS Ctrl+Alt+Esc
DTK BIOS Esc
Phoenix BIOS F1
Phoenix BIOS F2
Phoenix BIOS Ctrl+Alt+Esc
Phoenix BIOS Ctrl+Alt+S
Phoenix BIOS Ctrl+S
Phoenix BIOS Ctrl+Alt+Ins


III. GENERIC PC / BIOS

When you don't know any particulars for the computer or BIOS in question, or you don't see it in the lists above, start your attempts from the following key combinations:

Del
F1
F10
Ctrl+Alt+S
Ctrl+Alt+Enter
Ctrl+Alt+Ins
Ctrl+Alt+Esc
Ctrl+Alt+NumPad[+]
Ctrl+Esc

source: tsf
article by Zazula