How-toWindowsWindows 11

Windows 11: how to do a clean install from a USB drive

Erase a PC and install fresh Windows 11 from a USB drive built with Microsoft's own tool, with every Setup screen explained.

  • Updated
  • 45 min
  • Advanced
Applies to
  • Windows 11

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Wiping the drive and putting a fresh copy of Windows 11 on it is called a clean install. It suits people who want a fresh start, or whose PC has problems that nothing else fixed, and who are ready to restore their own files afterward.

This erases the drive

A clean install deletes everything on the drive you choose: Windows, programs, settings and your files. Continue only after your files are copied somewhere else and you have opened a few of the copies to check them.

The clean install in five stages5 numbered steps, one under the other. The full text follows the picture.The clean install in five stages1PrepareBack up files and find accountand key details2Make the USBBuild the installer withMicrosoft's tool3Boot from itOpen the boot menu and pickthe USB drive4InstallChoose Custom install andthe right drive5FinishRun Windows Update, thenrestore your files
Stages 1 and 2 are the ones that protect your files.
Text version of this diagram
  1. Prepare: Back up files and find account and key details
  2. Make the USB: Build the installer with Microsoft's tool
  3. Boot from it: Open the boot menu and pick the USB drive
  4. Install: Choose Custom install and the right drive
  5. Finish: Run Windows Update, then restore your files

Before you start

Allow about an hour, mostly waiting. You need a second working computer with internet to make the USB drive, and a blank USB flash drive of at least 8 GB. Plug a laptop into power for the whole process.

First check that the PC meets the requirements in Windows 11 system requirements: can your PC upgrade?. Microsoft says installing Windows 11 on a PC that does not meet them is not recommended, and that PC would no longer be supported or eligible for updates.

Back up and gather what you need

  1. Copy your documents, photos, browser bookmarks and anything else you value to an external drive or cloud storage. See how to back up your files.
  2. Write down the programs you use and where their licenses are kept.
  3. If the PC uses BitLocker drive encryption, find your recovery key first. Your Microsoft account is the usual place to look.
  4. Check that you can sign in to your Microsoft account on another device. Windows 11 Home needs internet and a Microsoft account to finish first-time setup.
  5. If you can, download the Wi-Fi or network driver for your PC model from the PC maker's support site onto a second USB drive or another computer. A fresh Windows normally finds the network on its own, but this saves you if it does not.

Official download only

Download the installer only from microsoft.com. Never use "pre-activated" copies, activators or cheap keys from unknown sellers, which are common ways malware spreads. You need your own Windows 11 license or a qualifying Windows 10 PC.

Make the installation USB drive

  1. On the second computer, plug in the blank USB drive. Everything on it will be deleted.
  2. Open Microsoft's Windows 11 download page. Under Create Windows 11 Installation Media, select Download Now.
  3. Right-click the downloaded file, select Run as administrator, then select Accept to agree to the license terms.
  4. Select Create installation media for another PC, then choose the language, edition and 64-bit architecture. Microsoft says the language should match the one your PC uses now. The tool cannot make media for Arm-based PCs.
  5. Choose USB flash drive and select your drive. Wait for the tool to finish. You will see a message that the drive is ready.

Start the PC from the USB drive

  1. Plug the USB drive into the PC that will get the fresh install, then turn it on. If the PC is already on, restart it.
  2. Press the boot menu key repeatedly as soon as the maker's logo appears. The key depends on the maker. Common ones are F12, Esc, F9 and F11, and a hint line on the first screen often names it. If you are unsure, check your PC's manual or the maker's support site.
  3. Use the arrow keys to select the USB drive, then press Enter.
  4. When you see Install Windows, confirm your language, time and keyboard settings, then select Next.
A typical boot menuA monitor showing a simple boot menu on a dark screen with the heading "Boot menu", three choices (internal drive, USB drive and network) with the first highlighted, and a hint bar at the bottom. It has 3 numbered markers, explained in the list under the picture.Boot menuInternal driveUSB driveNetworkEnter: select123A typical boot menu
  1. Each line is a drive the PC can start from
  2. The USB drive often shows "USB" or its brand name
  3. A hint bar lists the keys that move and select
Boot menus differ on every PC.
Text version of this diagram

A monitor showing a simple boot menu on a dark screen with the heading "Boot menu", three choices (internal drive, USB drive and network) with the first highlighted, and a hint bar at the bottom.

  1. Each line is a drive the PC can start from
  2. The USB drive often shows "USB" or its brand name
  3. A hint bar lists the keys that move and select

If the PC starts its old Windows

Restart and try the boot menu key again. If the PC is running Windows, you can instead open Settings then System then Recovery, select Restart now next to Advanced startup, and then choose Use a device.

If the USB drive never appears

First try another USB port, and look for two entries for the same drive: choose the one marked UEFI, because Windows 11 installs in UEFI mode. Firmware settings differ for every PC, and a wrong change can stop the PC starting. If you still need to change a firmware setting, follow your PC maker's instructions, change only that setting, and do not leave Secure Boot switched off, because Windows 11 expects it to be available.

Install Windows 11

Screen wording can differ a little between releases of the installer, but the order below is the usual one.

  1. Select Install Windows.
  2. If Setup asks for a product key and this PC ran an activated Windows before, select I don't have a product key. Many PCs have a digital license that Windows finds once the PC is online.
  3. If asked which edition to install, choose the one your PC had, such as Windows 11 Home.
  4. Accept the license terms.
  5. For the type of installation, select Custom: Install Windows only (advanced). Do not choose the upgrade option, which keeps files.
  6. On the screen Where do you want to install Windows 11?, look carefully at the list. Unplug extra drives beforehand.
Partitions you may see during setupA horizontal bar for one disk, divided left to right into four parts: a small EFI system partition, a large Windows partition, a recovery partition and a hatched block of unallocated space. It has 4 numbered markers, explained in the list under the picture.Disk 01234Partitions you may see duringsetup
  1. System (EFI) partition: files that start the PC
  2. Windows partition: the old Windows and your old files
  3. Recovery partition: repair tools
  4. Unallocated space: empty space Setup can use
A typical layout. Names and sizes differ between PCs.
Text version of this diagram

A horizontal bar for one disk, divided left to right into four parts: a small EFI system partition, a large Windows partition, a recovery partition and a hatched block of unallocated space.

  1. System (EFI) partition: files that start the PC
  2. Windows partition: the old Windows and your old files
  3. Recovery partition: repair tools
  4. Unallocated space: empty space Setup can use

Do not delete a data drive

If the list shows a second drive, such as a separate data disk, leave its partitions alone. Delete only the partitions on the drive that held Windows.

  1. Select the partitions on the drive that holds the old Windows (the Windows partition and the small system and recovery ones on the same drive) and select Delete for each. You can also leave them and install over the Windows partition. Deleting is the thorough clean start.
  2. Select the single block of Unallocated Space on that drive, then select Next. Setup creates the partitions it needs.
  3. Wait while files copy. The PC restarts several times. If a message asks you to press a key to start from the USB drive again, do not press one, so Setup continues from the internal drive. If the Install Windows page appears again, take out the USB drive and restart.
  4. Answer the setup questions: region, keyboard, network and account.

Check that it worked

  1. Open Settings then Windows Update and select Check for updates. Install what is offered and restart. Repeat until it says you are up to date.
  2. Open Settings then System then Activation. You should see that Windows is activated.
  3. Open Device Manager from the Start button's right-click menu. A yellow warning mark means a device is missing a driver. See how to fix driver problems. Get any missing drivers from Windows Update or your PC maker.
  4. Copy your files back, then add your programs using how to install software and apps.

If something goes wrong

Setup says Windows 11 cannot run on this PC

Your PC does not meet a requirement, often TPM 2.0 or Secure Boot. Do not look for ways around the check. Read the requirements guide first.

Windows is not activated afterward

Connect to the internet, wait a few minutes, and check Settings then System then Activation again. The page shows a message that explains the problem. A PC with no license needs one from Microsoft or an authorized seller.

You want to reset without installation media

Microsoft's Reset this PC reinstalls Windows without any installation media. Microsoft says you can keep your personal files or remove everything. It is under Settings then System then Recovery.

Frequently asked questions

Is a clean install better than an upgrade?

Not always. A clean install removes old software problems but means reinstalling everything. An upgrade keeps your programs and files. For a PC that works but is slow, try the fixes in common Windows 11 problems and fixes first.

Do I need a product key?

Often not. A PC that already ran activated Windows usually has a digital license. A PC with no license needs one from Microsoft or an authorized seller.

Can I use the USB drive for files afterward?

Yes, once the install is finished and you no longer need the installer. Format the drive first, and keep your own files off it while it is the installer.

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Official resources used

Pages consulted while preparing this guide. Check them for the latest details.

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