1. CS101
Booting A Computer

2. 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?

3. 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.

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

5. Why do we care how a computer starts?

6. 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

7. 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

8. 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

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