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BIOS Settings Overview

Jun 7, 2025

Overview

This lecture covers BIOS settings, including how to access, configure, and manage features like boot order, hardware control, security options, cooling management, and virtualization.

Accessing the BIOS

  • Enter BIOS setup by pressing a function key (e.g., Del, F1, F2, Ctrl+S) during system startup.
  • Hypervisors like VMware Workstation or Fusion allow BIOS access for VMs, while VirtualBox does not.
  • Fast startup in Windows 10/11 prevents BIOS access; fully shut down or restart using Shift+Restart or through Recovery options.
  • Disabling fast startup or interrupting the boot process multiple times can force BIOS access.

BIOS Configuration Best Practices

  • Document all BIOS changes to revert if needed.
  • Take photos or write down settings before making changes.
  • Avoid altering memory or CPU settings without understanding them.
  • Always backup BIOS configuration before making changes.

Boot and Hardware Settings

  • Configure boot order in BIOS to determine which device starts first (e.g., SSD, USB, network).
  • Enable or disable certain hardware (e.g., USB ports) from BIOS for security or functionality.

Cooling and System Monitoring

  • BIOS fan controls can prioritize performance, noise reduction, or run at full speed.
  • Modern motherboards use temperature sensors and fan controllers managed from BIOS.
  • Monitor hardware temperatures directly from BIOS.

Security Features

  • Enable Secure Boot in UEFI BIOS to block malware before OS starts and verify firmware integrity.
  • Secure Boot uses digital signatures for OS, BIOS, and bootloader verification.
  • Set BIOS-level passwords for user/boot and supervisor access to restrict unauthorized use and configuration changes.
  • Lost BIOS passwords require a full BIOS reset per manufacturer instructions.

BIOS Storage and Reset

  • Modern BIOS and settings are stored in non-volatile flash memory, not traditional CMOS.
  • Resetting BIOS often requires physical access to the motherboard, using a jumper (e.g., CLRTC for clearing settings).
  • Motherboard batteries are not used to store BIOS settings anymore.

Virtualization Support

  • Enable CPU virtualization features (Intel VT or AMD-V) in BIOS to optimize VM performance and stability.

Key Terms & Definitions

  • BIOS (Basic Input/Output System) — Firmware that initializes hardware and loads the operating system.
  • UEFI (Unified Extensible Firmware Interface) — Modern BIOS replacement with added features like Secure Boot.
  • Secure Boot — A security protocol that verifies digital signatures of firmware and OS before booting.
  • Flash Memory — Non-volatile storage used for BIOS firmware and settings.
  • Jumper — A connector used to reset BIOS settings by shorting motherboard pins.
  • Virtualization — Hardware-assisted technology for running multiple operating systems simultaneously.

Action Items / Next Steps

  • Practice accessing BIOS on your system or a VM.
  • Document any BIOS settings changed.
  • Review Secure Boot and virtualization options in your BIOS setup.
  • Ensure you have a backup of your current BIOS configuration.