BIOS: frequently asked questions

Applies to all editions of Windows Vista.
Which edition of Windows Vista am I using?

Here are answers to some common questions about BIOS.

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What is BIOS?

Basic input/output system (BIOS) is a program built into personal computers that starts the operating system when you turn on your computer. It is also referred to as system firmware. BIOS is part of the hardware of your computer and is separate from Windows.

Do I need to do anything with BIOS?

No, BIOS does not need to be managed and you do not need to change any settings. Advanced users might choose to change certain settings, such as the order in which the computer searches devices when starting.

What kind of BIOS does my computer have?

You can view general information about your computer's BIOS in System Information.

1.	Open System Information by clicking the Start button , clicking All Programs, clicking Accessories, clicking System Tools, and then clicking System Information.
2.	Click System Summary in the left pane, and then look under BIOS Version/Date in the right pane to view the BIOS manufacturer, version number, and the date the BIOS was released. For specific information about the BIOS used by your computer, check the information that came with your computer or go to the computer manufacturer's website.

How do CMOS and ACPI relate to BIOS?

Complementary metal oxide semiconductor (CMOS) refers to a chip inside your computer that saves your BIOS settings. As a result, the terms CMOS and BIOS are sometimes used interchangeably. For more information, see What is CMOS?

Advanced Configuration and Power Interface (ACPI) is an industry standard that defines power management features and other configuration information for computers. Some previous versions of BIOS do not support ACPI, and so the computer may not successfully enter advanced power modes such as sleep or hibernate. For more information, check the information that came with your computer or go to the computer manufacturer's website.

How do I access my computer's BIOS?

Procedures vary depending on the BIOS manufacturer. Usually, you must press a key (such as F2, F12, DEL, ESC) or a key combination immediately after you turn on your computer but before Windows starts. For more information, check the information that came with your computer or go to the computer manufacturer's website.

Be careful when changing BIOS settings. The BIOS interface is designed for advanced users, and it's possible to change a setting that could prevent your computer from starting correctly.

How do I update BIOS?

Procedures vary depending on the BIOS manufacturer. If you think you need to update your BIOS, check the information that came with your computer or go to the computer manufacturer's website.

Updating BIOS should only be done if necessary (to solve a compatibility problem, for example). It can be a complicated process, and if an error occurs, your computer could be rendered inoperable. Be sure to follow the manufacturer's instructions exactly.