CS101 Booting A Computer

Booting Up A Computer Dilemma To get our computer running we need the OS To survive when the computer is turned off the OS must be saved to a storage device, usually the hard drive The OS knows how to get software off of the hard drive so it can run on the computer, but the OS is in the hard drive when the computer tries to start so it cannot get itself out of the hard drive How does the computer start up without the OS?

Booting a computer When you press the Power button an electrical signal is sent to the to your systems Firmware Firmware has the special ability to be able to store zeros and ones without any power being supplied The firmware points to the UEFI hidden partition on the computers hard drive. The UEFI partition has boot loaders for all OS’s stored in partitions on the disk. The boot loaders go get the OS from the partition it is stored on and starts loading it into RAM and the processor.

Unified Extensible Firmware Interface UEFI Invented by Intel in mid - 1990’s Used by Macs and newer Windows computers Started being used large scale around 2005 - 2007.

Why do we care how a computer starts?

Once in Windows Advanced Startup Options you can… Do a system restore Set Windows back to earlier state Do a system recovery Do Startup Repair Change Startup Settings Change UEFI Firmware Settings. Enter Startup Repair Go back to previous build

Enter Windows 10 Advanced Startup options Click the Start menu and select Settings. Select Update and Security. Click Recovery. Under Advanced startup, click Restart now. ... Select Troubleshoot. Choose Advanced options

How to enter Mac Recovery Mode Hold down Command – R at startup Things you can do in recovery mode: Restore From Time Machine Backup Reinstall macOS Get Help Online Run Disk Utility Use Disk Utility to repair or erase your startup disk or other hard disk. Other utilities are available from the Utilities menu in the menu bar: Firmware Password Utility Network Utility Terminal

On Mac you can hold down keys at startup to effect settings. Startup key combinations for Mac