Hardware requirements by Windows version: 11 26H2, LTSC and Server

Verified 2026-10-292 min read

One matrix for TPM, Secure Boot, CPU support, RAM and storage across Windows 11 26H2, LTSC 2024, Server 2025 and Server 2022 — and what each rule protects.

Tested onPro (26H2) / Server · Build 26300.9457 / 26100.33650 · x64

Build: 26300.9457 / 26100.33650
Edition: Pro (26H2) / Server
Architecture: x64
Support: Documentation (E1)
Evidence: E1Official documentation
Verified: 2026-10-29
Page type: Vendor

The short answer

Windows 11 is the strict one: UEFI + Secure Boot capable + TPM 2.0 + a support-listed CPU. Windows Server does not require TPM or Secure Boot to install, but VBS/Credential Guard and BitLocker work better with them.

That asymmetry explains most “Server installs fine, Windows 11 refuses” surprises.

The matrix

Requirement	Windows 11 26H2	Windows 11 LTSC 2024	Server 2025	Server 2022
Firmware	UEFI	UEFI	UEFI or legacy	UEFI or legacy
Secure Boot	Capable, enabled by policy	Capable	Not required	Not required
TPM	2.0 required	2.0 required	Not required	Not required
CPU	Support list	Support list	Support list	Support list
RAM	4GB minimum	4GB minimum	2GB (Core) / 4GB	2GB / 4GB
Storage	64GB	64GB	32GB	32GB
Virtualization	Optional (VBS)	Optional	Optional (Hyper-V)	Optional
DirectX	12 / WDDM 2.0	12 / WDDM 2.0	Not applicable	Not applicable

The CPU support list is the part people skip. A CPU can be fast and still unsupported: Microsoft publishes the requirement that the processor be on the supported list for the Windows release, and OEMs only ship firmware for supported combinations. See CPU support checks.

What each rule actually protects

TPM 2.0 stores BitLocker keys, backs Windows Hello and Credential Guard, and measures boot state. Without it, Windows 11’s device encryption cannot work.
Secure Boot ensures only signed boot components run. It is also what makes some anti-cheat and anti-tamper features possible.
UEFI (not CSM) is required for Secure Boot and for features like memory integrity.
Supported CPU reduces the chance that firmware/microcode stops receiving fixes.

Server is not “Windows 11 without TPM”

Server drops the consumer requirements, but adds its own:

Drivers: server NICs/storage controllers must have Server-certified drivers. Consumer drivers often refuse to install.
Roles: Hyper-V requires SLAT; Storage Spaces Direct requires specific hardware.
Editions: Standard covers two OSEs, Datacenter unlimited — a licensing constraint that changes hardware planning more than any spec.

Check a machine before you install

# firmware mode, Secure Boot, TPM
Confirm-SecureBootUEFI
Get-Tpm | Select-Object TpmPresent,TpmReady,ManufacturerIdTxt
Get-CimInstance Win32_ComputerSystem | Select-Object Manufacturer,Model
(Get-CimInstance Win32_ComputerSystem).BootupState

# CPU identity and virtualization exposure
Get-CimInstance Win32_Processor | Select-Object Name,NumberOfCores,NumberOfLogicalProcessors,VirtualizationFirmwareEnabled

VirtualizationFirmwareEnabled : False on a CPU that supports it means the firmware switch is off — an easy fix that unlocks Hyper-V/VBS later.

Upgrade paths that avoid a reinstall

Windows 11 Pro → Enterprise: edition upgrade with a key, no reinstall.
Server evaluation → licensed edition: needs a valid key; plan storage and roles first.
Windows 10 → 11: the hardware checks above decide it; there is no supported bypass for TPM/Secure Boot.

Lab boundary

E1. Requirements are quoted from Microsoft’s published documentation. The lab machines (26H2 and LTSC 2024 VMs) satisfy them through OVMF + vTPM.