Unit 1OSObjective 1.211 min read

Installing and Upgrading Windows: Boot Methods, Installation Types, Partitioning, and Upgrade Considerations

Unit 1: Operating Systems and Installation. Lesson 3 of 41 in APlus Academy Core 2.

Installing an operating system is a chain of choices: where to boot from, what kind of installation, how to partition and format, and what to check before upgrading. The exam tests each link.

Boot methods

The installer has to come from somewhere the firmware can boot.

USB: a bootable flash drive made with the vendor's media tool; the everyday method.
Network: PXE (Preboot Execution Environment) boot from the NIC, pulling the installer from a deployment server; used in offices to install dozens of machines.
Solid-state or flash drive: an installer or image on an SSD or memory card.
Internet-based: cloud recovery built into modern firmware or the OS (macOS Internet Recovery, Windows cloud download in Reset this PC).
External or hot-swappable drive: an external SSD or a drive in a dock.
Internal hard drive partition: a recovery or setup partition on the same disk.
Multiboot: two or more operating systems on one machine with a boot menu choosing between them.

Set the boot order in firmware or use the one-time boot menu.

Types of installations

Clean install: erase the target and install fresh. The best cure for a corrupted or malware-ridden system; data must be backed up first and applications reinstalled.
Upgrade (in-place): the new version installs over the old and keeps files, applications, and settings.
Image deployment: a reference machine is prepared and captured as an image, then copied to many machines (cloning tools, Microsoft Deployment Toolkit, Configuration Manager). Every machine comes out identical.
Remote network installation: boot from PXE and install from a server, no local media.
Zero-touch deployment: the device ships straight to the user; on first boot it contacts the vendor's service (Windows Autopilot), enrolls in management, and configures itself. Nobody in IT touches it.
Recovery partition: the manufacturer's hidden partition restores the factory image; it also restores the bloatware.
Repair installation: reinstalling Windows over itself from the same version's media to repair system files while keeping data and apps.
Third-party drivers: when setup cannot see the disk (RAID or unusual NVMe controllers), load the storage driver from a USB drive during setup.

Partitioning and formatting

A disk is divided into partitions, each formatted with a filesystem.

GPT (GUID partition table): the modern scheme for UEFI systems, up to 128 partitions, disks over 2 TB, protective backup of the partition table. Required for UEFI boot.
MBR (master boot record): the legacy scheme for BIOS systems, at most four primary partitions (or three plus an extended partition holding logical drives), a 2 TB limit.
Windows setup creates a small system partition and the main NTFS partition automatically; the drive format is NTFS for Windows, and the installer can convert between MBR and GPT during setup.
Mismatching firmware mode and partition style (legacy BIOS with GPT, or UEFI with MBR) produces "no bootable device."

Upgrade considerations

Before an in-place upgrade or version change:

Back up files and user preferences; an upgrade that fails halfway can leave a machine unbootable.
Check application and driver support and backward compatibility: the vendor's list of supported versions, especially for security software and old line-of-business apps.
Check hardware compatibility: the upgrade advisor or the vendor's requirements (Windows 11's TPM and CPU list).
Understand feature updates: Windows ships a yearly feature update that changes behavior, separate from monthly quality updates; test before deploying.
Know the product life cycle: upgrading to a version near its own EOL only postpones the problem.

Free space, a charged battery or AC power, and time are the practical requirements.

After setup finishes

Setup ends at the desktop, not at a finished machine. Install the vendor's drivers and let Windows Update run, create the user's account and join the domain if the office has one, then restore the backed-up files and open a few to prove the restore worked. On a clean install the applications go back on at this point too.

Exam tip: PXE is network boot; Autopilot-style zero-touch means nobody touches the device; image deployment makes clones. GPT needs UEFI and allows disks over 2 TB and 128 partitions; MBR is four primaries and 2 TB. Load third-party storage drivers when setup cannot see the disk. Back up before any upgrade.

Remember

Boot: USB, PXE network, SSD or flash, internet recovery, external drive, internal partition, multiboot. Types: clean, upgrade (keeps everything), image deployment (clones), remote network install, zero-touch (self-enrolls), recovery partition (factory), repair install (over itself), third-party storage drivers. GPT: UEFI, 128 partitions, over 2 TB; MBR: BIOS, 4 primaries, 2 TB. Upgrade: back up, app and driver support, hardware compatibility, feature updates, life cycle.

Deeper explanation

Installing and Upgrading Windows: Boot Methods, Installation Types, Partitioning, and Upgrade Considerations, explained slowly

Installation as a supply chain

An installation starts with media, chooses a method, lays down partitions, and then hands over to the operating system. Each stage has a menu of options, and the exam wants you to pick the right item for the scenario: a hundred identical machines, one corrupted laptop, a disk the installer cannot see, a machine shipped straight to a remote employee.

Boot methods compared

method                    when                                                 note
USB                       one machine, on site                                  media creation tool; boot order or one-time boot menu
network (PXE)             many machines in an office                            NIC boots, DHCP points to the deployment server
solid-state or flash      installer or image on an SSD or card                  fast; same as USB in practice
internet-based            no media at hand; cloud recovery                      Reset this PC with cloud download; macOS Internet Recovery
external or hot-swappable drive   an OS on an external SSD, or install from one   USB or Thunderbolt enclosure; dock bays
internal partition        recovery or setup files on the same disk              vendor recovery partitions
multiboot                 two operating systems on one machine                  boot menu (GRUB or the Windows boot manager) picks one

Installation types compared

type                       keeps data?   keeps apps?   scale         typical use
clean install              no            no            one           fresh start, malware cleanup, new disk
upgrade (in-place)         yes           yes           one           new version, same machine
image deployment           n/a (replaces)   baked in   many          identical office PCs
remote network installation   no         no            many          PXE plus a server share
zero-touch deployment      new device    pushed later  many, remote  Autopilot-style self-enrollment
recovery partition         no            factory set   one           restore to factory condition
repair installation        yes           yes           one           fix system files without losing anything

Third-party drivers are a step inside any of these when the installer cannot see the storage controller: click Load driver and point at a USB stick with the vendor's storage driver.

Partition styles side by side

                MBR                                  GPT
firmware        legacy BIOS (or UEFI in CSM mode)    UEFI
partitions      4 primary, or 3 plus extended        128
maximum disk    2 TB                                 effectively unlimited
table backup    none                                 copy at the end of the disk, CRC checked
Windows boot    active primary partition             EFI System Partition (FAT32) plus MSR
convert         MBR2GPT tool without data loss (Windows 10 and later), or diskpart convert (destroys data)

Formatting is separate from partitioning: after the partition exists, format gives it a filesystem (NTFS for Windows). The Windows installer does both when you choose an unallocated space.

The upgrade checklist, expanded

Back up files and preferences (File History, cloud sync, an image of the disk for the cautious).
Application and driver support: check each critical application's vendor for the new version; antivirus, VPN clients, and old printers are the usual casualties; back-compat is not guaranteed.
Hardware compatibility: the vendor's checker (Windows 11's PC Health Check); firmware updates from the PC maker first.
Feature updates: read what changes in the yearly feature release; pilot on a few machines; defer if a line-of-business app breaks.
Product life cycle: install a version with years of support left; do not upgrade into a version near its own EOL.
Practical: enough free space (tens of GB), AC power, time, and the product key or a digital license.

Worked examples

A school receives 200 identical laptops. Image deployment: prepare one, capture, deploy by PXE or USB; or zero-touch enrollment if the laptops were ordered with Autopilot registration so students unbox them and they configure themselves.
A remote employee's new laptop arrives at their house. Zero-touch: they sign in, the device enrolls in management, and policies and apps arrive.
A laptop with a new NVMe controller shows no drives during setup. Load the storage driver from USB.
A PC upgraded from Windows 10 to 11 crashes constantly; the vendor's utility is not supported yet. Roll back within ten days, or clean install after the vendor ships support.
A 4 TB disk shows only 2 TB. It was initialized as MBR; reinitialize as GPT (data loss) or convert.

How the exam asks it

"Which boot method installs Windows from a deployment server without local media?" Network (PXE).
"A technician must set up 50 identical PCs. Most efficient method?" Image deployment.
"A new device configures itself on first boot after the user signs in." Zero-touch deployment.
"Which partition style is required for a UEFI system to boot?" GPT.
"How many primary partitions can an MBR disk hold?" Four.
"Setup cannot see the SSD." Load third-party storage drivers.
"What should be done before an in-place upgrade?" Back up files and settings and verify application and hardware compatibility.

What to memorize

Boot methods and installation types by scenario.
GPT: UEFI, 128 partitions, over 2 TB. MBR: BIOS, four primaries, 2 TB. Format after partition.
Upgrade considerations: backup, application and driver support, hardware compatibility, feature updates, product life cycle.