How To Windows BIOS (Basic Input Output System) Everything You Need to Know About BIOS Share Pin Email Print BIOS Setup Utility (Main Menu). Windows Key Concepts Computer Concepts File Types Command Line Basics Guides & Tutorials Installing & Upgrading Tips & Tricks by Tim Fisher Updated April 24, 2018 BIOS, which stands for Basic Input Output System, is software stored on a small memory chip on the motherboard. You might need to access BIOS to change how the device works or to assist in troubleshooting a problem. It's BIOS that's responsible for the POST and therefore makes it the very first software to run when a computer is started. The BIOS firmware is non-volatile, meaning that its settings are saved and recoverable even after power has been removed from the device. Note: BIOS is pronounced as by-oss and is sometimes referred to as the System BIOS, ROM BIOS, or PC BIOS. However, it's also incorrectly referred to as the Basic Integrated Operating System or Built in Operating System. What Is the BIOS Used For? BIOS instructs the computer on how to perform a number of basic functions such as booting and keyboard control. BIOS is also used to identify and configure the hardware in a computer such as the hard drive, floppy drive, optical drive, CPU, memory, etc. How to Access BIOS The BIOS is accessed and configured through the BIOS Setup Utility. The BIOS Setup Utility is, for all reasonable purposes, the BIOS itself. All available options in BIOS are configurable via the BIOS Setup Utility. Unlike an operating system like Windows, which is often downloaded or obtained on a disc, and needs to be installed by the user or manufacturer, BIOS is pre-installed when the computer is purchased. The BIOS Setup Utility is accessed in various ways depending on your computer or motherboard make and model. See How to Access the BIOS Setup Utility for help. BIOS Availability All modern computer motherboards contain BIOS software. BIOS access and configuration on PC systems is independent of any operating system because the BIOS is part of the motherboard hardware. It doesn't matter if a computer is running Windows 10, Windows 8, Windows 7, Windows Vista, Windows XP, Linux, Unix, or no operating system at all—BIOS functions outside of the operating system environment and is no way dependent upon it. Popular BIOS Manufacturers The following are some of the more popular BIOS vendors: Phoenix TechnologiesIBMDellGatewayBYOSOFTAmerican Megatrends (AMI)Insyde Software Note: Award Software, General Software, and Microid Research were BIOS vendors that were acquired by Phoenix Technologies. How to Use BIOS BIOS contains a number of hardware configuration options that can be changed through the setup utility. Saving these changes and restarting the computer applies the changes to the BIOS and alters the way BIOS instructs the hardware to function. Here are some common things you can do in most BIOS systems: Change the Boot OrderLoad BIOS Setup DefaultsRemove a BIOS PasswordCreate a BIOS PasswordChange the Date and TimeChange Floppy Drive SettingsChange Hard Drive SettingsChange CD/DVD/BD Drive SettingsView Amount of Memory InstalledChange the Boot Up NumLock StatusEnable or Disable the Computer LogoEnable or Disable the Quick Power On Self Test (POST)Enable or Disable the CPU Internal CacheEnable or Disable the Caching of BIOSChange CPU SettingsChange Memory SettingsChange System VoltagesEnable or Disable RAIDEnable or Disable Onboard USBEnable or Disable Onboard IEEE1394Enable or Disable Onboard AudioEnable or Disable Onboard Floppy ControllerEnable or Disable Onboard Serial/Parallel PortsEnable or Disable ACPIChange the ACPI Suspend TypeChange the Power Button FunctionChange Power-on SettingsChange Which Display is Initialized First on Multi-Display SetupsReset Extended System Configuration Data (ESCD)Enable or Disable BIOS Control of System ResourcesChange Fan Speed SettingsView CPU and System Temperatures View Fan SpeedsView System Voltages More Information on BIOS Before updating BIOS, it's important to know what version is currently running on your computer. There are multiple ways to do this, from checking in the Windows Registry to installing a third-party program that will display the BIOS version. If you need help, see our How to Check the Current BIOS Version on Your Computer guide. When configuring updates, it's extremely important that the computer not be shut down partway through or the update cancelled abruptly. This could brick the motherboard and render the computer unusable, making it difficult to regain functionality. One way this is avoided is for BIOS to use what's called a "boot lock" section of its software that gets updated on its own apart from the rest so that if corruption is found, a recovery process can be undergone to prevent damage. BIOS might check if the full update has been applied by verifying that the checksum matches up with the intended value. If it doesn't, and the motherboard supports DualBIOS, that BIOS backup can be restored to overwrite the corrupted version. The BIOS in some of the first IBM computers were not interactive like modern-day BIOSes but instead only served to display error messages or beeps codes. Any custom options were instead made by modifying physical switches and jumpers. It wasn't until the 1990s that the BIOS Setup Utility (also known as the BIOS Configuration Utility, or BCU) became common practice. However, nowadays, BIOS has slowly been being replaced by UEFI (Unified Extensible Firmware Interface) in newer computers, which offers benefits like a better user interface and a built-in, pre-OS platform for accessing the web. Was this page helpful? Thanks for letting us know! Share Pin Email Tell us why! Other Not enough details Hard to understand Submit Continue Reading