Once the hardware is together, a new PC still needs an operating system. For almost every UK gaming or work build, that means Windows 11, installed from official Microsoft media rather than a random USB stick. This guide covers a clean install on a new desktop, which is the usual last step after our beginner's build guide.
The steps below follow Microsoft's own download and installation pages. Forge PC hasn't recorded a fresh install for this article, and we don't recommend installing Windows 11 on a PC that fails Microsoft's minimum requirements. If you are choosing an edition first, see our Windows 11 Home vs Pro comparison.
What you need
From Microsoft's Windows 11 specification page, the PC must have:
A compatible 64-bit processor or SoC, running at 1GHz or faster with two or more cores
4GB of RAM (you'll want much more for a gaming or work PC; see how much RAM you need)
64GB or more of storage
UEFI firmware that is capable of Secure Boot
TPM 2.0
A DirectX 12 / WDDM 2.0 graphics device and a 720p display
Microsoft also says that Windows 11 Home, and Windows 11 Pro for personal use, require an internet connection and a Microsoft account during the first set-up.
For the installer itself, Microsoft's download page (which currently offers Windows 11 2026 Update, version 26H2) asks you to use the Media Creation Tool if you want a bootable USB for a new or different PC. You will need:
A Windows 11 licence, or a qualifying Windows 10 licence
A USB flash drive of at least 8GB, which will be erased
Another working PC with an internet connection and administrator rights, to run the tool
The tool itself, downloaded from Microsoft's official Windows 11 download page — not a third-party "Windows USB" site
The Media Creation Tool creates media for x64 PCs only. Microsoft says it cannot be used to make installers for Arm-based PCs.
On a working PC:
Download the Windows 11 Media Creation Tool from Microsoft's official software-download page.
Run it as an administrator and accept the licence terms.
Choose Create installation media for another PC and continue.
Select the language, edition and 64-bit architecture.
Choose USB flash drive, plug in the blank 8GB-or-larger stick, and let the tool write the media. Anything already on the drive will be deleted.
If you prefer, Microsoft also lets you download an ISO and burn a DVD of at least 8GB, or mount the ISO on an existing Windows PC. For a new empty machine, a USB stick is the practical option.
Step 2: Get the new PC ready to boot from USB
On the new build, connect a keyboard, mouse, display (into the graphics card if you have one, not the motherboard ports), and the USB installer. Turn the PC on and open the boot menu or firmware settings. Microsoft notes that this is usually a key such as F2, F12, Delete or Esc, pressed just after power-on; your motherboard manual will say which one.
Two firmware settings matter if the installer complains, or if the stick doesn't appear in the boot list:
UEFI boot, not old legacy BIOS mode
TPM 2.0 and Secure Boot enabled, if they are not already. Microsoft's specification page explains both requirements. Some boards hide TPM under a name such as fTPM (AMD) or PTT (Intel).
If the USB device doesn't appear at all, Microsoft says you may need to look up the board maker's instructions for temporarily disabling Secure Boot. Change only what you have to, and put Secure Boot back on once Windows is installed if you had to turn it off to boot the stick.
Step 3: Install Windows
Microsoft's download page, once the PC has booted from the USB drive, has you choose your language, time and keyboard, then select Install Windows. After that, follow the on-screen installer: enter a product key if you have one, or add it later if the installer allows (a digital licence tied to your Microsoft account can also activate after set-up), and choose the edition that matches your licence.
If this is a new, empty drive you are happy to wipe, select that disk as the destination. Installing over the wrong drive is the expensive mistake — check you have picked the new SSD, not a second disk with files on it. Our SSD guide is about choosing that drive, not about partitioning. Let the installer copy files. The PC will restart several times. Don't turn it off.
If you changed the boot order to force the USB stick to go first, Microsoft warns that the "Install Windows" screen can reappear after the install finishes. In that case, change the boot order back so the internal drive is first.
Step 4: First boot and a Microsoft account
On a Home or personal Pro install, Microsoft requires a Microsoft account and an internet connection to complete set-up. Have a network cable or working Wi-Fi ready; for a desktop, Ethernet is the least frustrating option (see our Wi-Fi vs Ethernet guide if you have a choice).
After you reach the desktop:
Run Windows Update until it stops offering new patches, then restart if asked.
Install the motherboard chipset driver from the board maker, then the graphics driver from NVIDIA, AMD or Intel — not a third-party driver pack.
Turn on your memory profile (EXPO or XMP) in the BIOS if you haven't already, so the RAM runs at its rated speed. That is covered in more detail in our RAM guide.
Activate Windows in Settings if it is not already activated.
A new build that is missing chipset or graphics drivers can look worse than it is. Get those official installers before you start changing game settings or blaming the hardware.
If something goes wrong
The USB stick is ignored: confirm it was written by Microsoft's tool, try another USB port (preferably one on the back of the board), and check the boot menu. USB 2.0 ports sometimes behave more simply than front-panel USB-C.
The installer says the PC doesn't meet requirements: check TPM, Secure Boot and UEFI. Microsoft warns that installing anyway on an unsupported PC means it "will no longer be supported and won't be entitled to receive updates," and that damage from incompatibility isn't covered by the manufacturer warranty.
No display: the monitor may be plugged into the motherboard instead of the graphics card. That is a hardware issue, not a Windows one — see the boot-fix guide.
Our verdict
Install Windows 11 from Microsoft's official Media Creation Tool, on a USB drive of at least 8GB that you are happy to erase, and boot the new PC in UEFI mode with TPM 2.0 and Secure Boot enabled. Use the edition you have a licence for, wipe only the disk you intend to, and finish set-up with a Microsoft account and an internet connection, which Microsoft requires on Home and personal Pro installs. Then update Windows, add official chipset and graphics drivers, and enable EXPO or XMP. Skip unofficial "Windows USB" tools, and don't install on hardware that fails Microsoft's requirements if you want to stay on the supported update path.
