Installing Operating Systems - CompTIA A+ 220-1202 - 1.2

Understanding Operating System Installation

The Chicken and the Egg Problem

• Installing an operating system poses a paradox: without an OS, how can one install it? This is typically resolved by booting from an installation program running in a minimal OS environment.

Bootable USB Drives

• A common solution involves creating a bootable USB drive using specialized software, which must be supported by the motherboard to initiate the installation process. All necessary installation files are stored on this drive.

Network Booting (PXE)

• In scenarios where USB interfaces are unavailable or impractical, network booting (PXE) allows computers to load an OS over the network. The BIOS must support PXE functionality to locate and connect to a PXE server for installation.

Alternative Installation Methods

Internet-Based Installations

• Some systems can download OS files directly from the internet during installation, such as certain Linux distributions or MacOS recovery installations that fetch necessary files online. Windows also supports direct installations via updates.

ISO Images

• An ISO image encapsulates all data from an optical disc into a single file format, facilitating easy setup for virtual machines or external drives that mimic physical discs for installations across different computers.

Local vs Remote Installations

Internal Drive Installations

• Installation files can be copied onto internal drives, allowing users to boot directly from these partitions for installing new operating systems alongside existing ones in a multi-boot configuration.

Clean vs In-place Upgrades

• Users have options when installing: a clean install wipes all previous data while an in-place upgrade retains applications and user data during the update process of existing systems.

Streamlined Deployment Processes

Image Deployment

• Organizations often create deployment images after configuring an OS with required applications and settings, enabling rapid deployment across multiple devices with minimal manual intervention. This process can be fully automated for efficiency.

Recovery Partitions

• Many modern operating systems include hidden recovery partitions containing essential installation files for troubleshooting purposes without needing external media during repairs or reinstalls.

Repair Installations and Driver Issues

Repair Installations

• Windows offers repair installations that overwrite system files while preserving user documents, useful for resolving significant issues without complete data loss during troubleshooting efforts.

Third-party Drivers During Installation

• If default drivers do not recognize hardware components during setup, users may need to manually load third-party drivers through prompts provided in the installation interface to ensure proper connectivity and functionality of devices being installed upon completion of the OS setup process.

Zero-Touch Deployments

Automated User Experience

• Zero-touch deployments automate installations with minimal user input required; configurations specific to corporate environments are applied automatically as part of this streamlined process, enhancing productivity right out of the box for remote users globally.

Disk Partitioning Essentials

Creating Disk Partitions

• Before installing an OS, it's crucial to partition storage drives logically; some systems prefer multiple partitions while others function well with just one large partition dedicated solely to data storage needs like recovery or dual-operating system setups.

Partition Styles: GPT vs MBR

GPT Partition Style

• The GPT (GUID Partition Table) style allows up to 128 partitions per drive and requires UEFI BIOS compatibility; it supports vast storage capacities exceeding traditional limits set by older methods like MBR (Master Boot Record).

MBR Limitations

• MBR restrictively supports only four primary partitions per drive; if more are needed, extended logical partitions must be created within one extended partition—these cannot be booted directly unlike primary ones.

Formatting Drives

Quick Format vs Full Format

• During Windows installations, users choose between quick formats—which merely create file tables—and full formats that thoroughly erase previous data by writing zeros across entire disks; each has implications on speed versus security regarding recoverability of old information.