Summary
Highlights
The video begins by explaining how to access system BIOS settings, typically by pressing a function key (Delete, F1, F2), or a combination of keys (Control-S, Control-Alt-S) during system startup. It also mentions accessing BIOS through desktop hypervisors like Hyper-V, VMware Workstation, or VMware Fusion, noting VirtualBox does not support this. Alternatively, online UEFI BIOS simulators can be used.
Windows 10 and 11 use 'fast startup,' which prevents the BIOS setup from being accessible during a normal shutdown. To fully shut down and access BIOS, users can hold Shift while clicking restart, navigate through Settings > Update and Security > Recovery > Advanced Startup, or use the msconfig utility. Interrupting the boot process three times can also force a complete restart.
Changing BIOS settings can lead to system instability or boot failure. It is crucial to document all changes, understand what each setting does, and have a backup of the configuration. Random changes to memory and CPU settings are particularly risky.
The BIOS is the first software to run and controls hardware access. Disabling hardware in the BIOS makes it invisible to the operating system. The BIOS also configures the boot order, determining which storage device the system attempts to boot from first (e.g., SATA, M.2, USB, network).
USB connections can be enabled or disabled in the BIOS for security reasons, as USB drives have been used to introduce malware. An example is the 2008 SillyFDC worm incident in the U.S. Department of Defense. Disabling USB ports via the BIOS is a measure to prevent unauthorized data transfer or malware injection.
Motherboards typically have temperature sensors and integrated fan controllers configured within the BIOS. These allow the system to monitor temperatures and adjust fan speeds to maintain optimal cooling, offering options like 'best performance,' 'best experience' (for quieter operation), or 'full speed.'
Secure Boot, a feature of UEFI BIOS, protects against malware loading before the operating system starts. It uses digital signatures to verify the integrity of the operating system, BIOS firmware, and bootloader. If an unrecognized change or unsigned software is detected, the boot process is halted. Users might need to disable Secure Boot for older operating systems but should re-enable it for modern systems.
BIOS offers password protection: a 'boot password' (user password) prevents unauthorized system startup, and a 'supervisor password' (BIOS password) prevents unauthorized changes to BIOS settings. Forgetting these passwords requires a BIOS reset, often involving physical access to the motherboard and a jumper.
BIOS software (firmware) and configuration settings are stored in flash memory on the motherboard. While older systems used CMOS memory backed by a battery, modern systems use non-volatile flash memory, meaning removing the battery does not reset the BIOS. Resetting typically involves shorting specific pins on the motherboard with a jumper (e.g., CLRTC pins on an ASUS motherboard).
Motherboards have numerous temperature sensors for the CPU, memory, and other components. Most BIOS configurations include a temperature monitoring feature, allowing users to view system temperatures directly within the BIOS before the operating system loads, which is useful for verifying cooling after hardware changes.
Hardware virtualization features, built into the CPU, can be enabled or disabled in the BIOS to enhance the stability and speed of virtual machines. Intel CPUs support Intel Virtualization Technology (VT), while AMD CPUs support AMD Virtualization (AMD-V). These settings are typically found under advanced CPU setup options.