To clean install Windows 10, make a Windows 10 installation USB with Microsoft’s Media Creation Tool, start the PC from the USB, and select Install now. Choose Custom: Install Windows only (advanced), delete the partitions on the drive where Windows goes, select the Unallocated Space, and select Next. Everything on that drive is erased, so back up first.
Applies to: Windows 10. Checked against Microsoft Support on September 26, 2026.
This works for reinstalling Windows 10, putting it on a new SSD or hard drive, and setting up a PC that has no operating system. If you’re replacing Windows 7, read moving from Windows 7 to Windows 10 or 11 first, because you’ll need a new license.
Before you start: Windows 10 support ended on October 14, 2025. A Windows 10 PC only gets security updates if it’s enrolled in Extended Security Updates (ESU). If your PC can run Windows 11, Microsoft recommends moving to Windows 11 instead. If you only want a fresh start and Windows still works, Reset this PC is simpler.
What you need
- A USB flash drive with at least 8 GB. It will be erased.
- A backup of your files. See how to back up Windows 10.
- A Windows 10 license. A PC that already ran activated Windows 10 usually has a digital license and reactivates on its own.
Step 1: Make the installation USB
On a working PC, download the Media Creation Tool from Microsoft’s Windows 10 download page. Run it, choose Create installation media (USB flash drive, DVD, or ISO file) for another PC, and pick your USB drive. See how to create a bootable Windows 10 USB for the full steps.
Step 2: Start the PC from the USB
Plug the USB into the PC and turn it on. Press the boot menu key as it starts (often F12, F11, Esc, or F9, depending on the PC maker) and pick the USB drive. See how to boot from USB in Windows 10 if it doesn’t show up.
Step 3: Install Windows 10
- Choose your language, time, and keyboard, then select Next > Install now.
- On the Activate Windows screen, enter your product key. If you’re reinstalling on a PC that already had activated Windows 10, select I don’t have a product key. Windows activates on its own once it’s online.
- If asked, choose the edition your license is for, such as Windows 10 Home or Windows 10 Pro. If you need Pro and only have a Home license, see how to download Windows 10 Pro and upgrade from Home.
- Accept the license terms, then select Custom: Install Windows only (advanced).
- On Where do you want to install Windows?, select each partition on the drive you’re installing to (usually Drive 0) and select Delete, until only Drive 0 Unallocated Space is left. Don’t change partitions on other drives.
- Select the Unallocated Space and select Next. Windows creates the partitions it needs and installs.
The PC restarts a few times. When the setup screens appear, choose your region and keyboard, and sign in or create an account.
Step 4: After it installs
- Check activation. Go to Settings > Update & Security > Activation. If you signed in with the Microsoft account linked to your license, Windows activates automatically.
- Get updates and drivers. Run Windows Update, and get any missing drivers from your PC maker.
- Restore your files from your backup.
Frequently asked questions
Does a clean install delete everything?
Yes, on the drive you install to. Your files, apps, and settings are removed. Other drives you don’t touch keep their files.
Do I need a product key to reinstall?
Usually not. A PC that had activated Windows 10 reactivates with its digital license. A new PC, or one where you replaced the motherboard, needs a license. If the PC currently runs Windows 7, see how to install Windows 10 from Windows 7 for the license rules that apply.
Can I install from a DVD?
Yes. Choose ISO file in the Media Creation Tool, burn it to a DVD, and start the PC from the DVD instead. Our guide on how to download Windows 10 on a laptop covers the ISO file option.
If your PC has a DVD drive and no spare USB drive, see how to burn a Windows 10 ISO to a DVD.
Microsoft’s guide is Reinstall Windows. More help is on our Windows Help & Guides page.
Matt Jacobs has been working as an IT consultant for small businesses since receiving his Master’s degree in 2003. While he still does some consulting work, his primary focus now is on creating technology support content for SupportYourTech.com.
His work can be found on many websites and focuses on topics such as Microsoft Office, Apple devices, Android devices, Photoshop, and more.