Clean Install Windows 11 from USB: A Careful Walkthrough

When you clean install Windows 11, setup wipes the system drive and puts a fresh copy of Windows on it, with no old apps, drivers or settings carried over. It is the most thorough reset you can do, and it works even when Windows will not start. It is also the one method with no undo, so this guide spends as much time on preparation as on the install itself. You will need a Windows 11 USB drive, about an hour, and a backup of anything you care about.

Clean install or something gentler?

Before you wipe anything, make sure you need to. Windows 11 has several recovery options that keep more of your data:

Option	Keeps files	Keeps apps	Needs USB
Fix problems using Windows Update	Yes	Yes	No
In-place reinstall from ISO	Yes (or your choice)	Yes (or your choice)	No, mount the ISO
Reset this PC	Optional	No	No
Clean install from USB	No	No	Yes

If Windows still runs and you only want to fix corruption, see reinstalling Windows 11 and keeping your files. If you want a fresh start but would rather not deal with USB drives and partitions, Reset this PC gets you most of the way there. A clean install makes the most sense when you are replacing a drive, selling or reusing a PC, removing a stubborn infection, or Windows will not boot at all.

Prepare before you start

Back up your files. Copy documents, photos, browser data and anything else you need to an external drive or to OneDrive. A clean install deletes everything on the drive you install to.

Save your BitLocker recovery key. Many Windows 11 PCs have device encryption or BitLocker turned on. You will not need the key to wipe the drive, but you will need it if you change your mind and want data back from the old installation, or if other encrypted drives are involved. Microsoft explains where to find it on its device encryption page, and our BitLocker recovery guide covers the common places it is stored.

Check your license. Go to Settings > System > Activation. If it says Windows is activated with a digital license linked to your Microsoft account, you are set. If you have a 25-character product key, write it down. Our Windows 11 product key guide explains how to find one.

Note your edition. Settings > System > About shows whether you have Home or Pro. Reinstall the same edition so the license matches.

Download drivers for networking. On some PCs, particularly newer laptops, the Wi-Fi adapter may not work until a driver is installed. Download the network driver from your PC maker’s support site onto a second USB drive, or have an Ethernet cable ready.

Create the installation USB

Build a Windows 11 USB of at least 8 GB with Microsoft’s Media Creation Tool. Our bootable USB guide has the full steps, including the Arm64 route. If you already have an ISO, see the Windows 11 ISO download guide for how to check its hash first.

Boot from the USB

1. Plug the USB drive into the PC.
2. Shut the PC down fully (Start > Power > Shut down), then turn it on and press the boot menu key. It is often F12, F2, Esc or Delete, but check your PC maker’s documentation.
3. Choose the USB entry, often labelled with “UEFI”.

If you see the Windows 11 setup screen, you are in the right place.

Run setup

1. Choose your language, time format and keyboard, then select Next.
2. Choose Install Windows 11. Read and tick the box confirming that files, apps and settings will be deleted if the screen asks for it.
3. When asked for a product key, enter it if you have one. If the PC already ran an activated Windows 11 or Windows 10, select I don’t have a product key; it should activate on its own once online.
4. If you are asked to choose an edition, pick the one that matches your license.
5. Accept the license terms.

Choose the drive and remove old partitions

This is the step that needs care. The installer lists every drive and partition it can see, labelled Disk 0, Disk 1 and so on.

1. Identify the drive you are installing to by its size. If the PC has more than one drive and you are not certain which is which, shut down and disconnect the others first.
2. On that drive only, select each partition (System, MSR, Primary, Recovery) and choose Delete partition. Confirm each one.
3. When the drive shows as a single block of unallocated space, select it and continue. Setup creates the partitions it needs.

Do not delete partitions on other disks unless you mean to erase them. There is no recycle bin here.

Setup now copies files and restarts several times. Remove the USB drive when the PC restarts for the first time, or make sure the internal drive is first in the boot order, otherwise setup may start again from the beginning.

Finish setup and get up to date

The out-of-box screens ask for region, keyboard and network. Windows 11 Home needs an internet connection and a Microsoft account to finish setup. On Pro, read the screens carefully: options depend on whether you are setting up for personal use or for work or school.

Once you reach the desktop:

1. Open Settings > System > Activation and confirm Windows is activated.
2. Open Settings > Windows Update and select Check for updates. Repeat until nothing new appears.
3. Install chipset, graphics and other drivers from your PC maker’s support site. Get graphics drivers from your PC maker or the GPU vendor rather than from driver-updater apps.
4. Restore your files from the backup.

If activation fails after a clean install, it is usually because the edition does not match the license or the hardware changed significantly. The Activation page in Settings has a Troubleshoot option that can help.