How to Install Windows From a USB Drive

What you need before you start

Installing Windows from USB means booting your computer from a USB stick instead of your hard drive, then running the Windows installer from that stick. You'll need a USB drive with at least 8 GB of space (16 GB is safer), a working computer to prepare the USB drive on, and a Windows installation file. Microsoft provides these files free on their website — you don't need to buy anything.

You'll also need to know your product key if you have one, though Windows will let you skip this step during installation and enter it later. If you're replacing an existing Windows installation, back up any files you want to keep first — this process will erase your hard drive.

The USB drive will be erased during preparation, so move any files off it before you start. The whole process takes about 30 minutes to prepare the USB drive, then 15 to 45 minutes to install Windows on your computer, depending on your hardware.

Key Takeaways

Download the Windows installation file from Microsoft's website using another computer, then use the Media Creation Tool to transfer it to your USB drive.
The USB drive will be completely erased during this process, so back up anything on it first.
Restart your computer and change the boot order in BIOS or UEFI so it starts from the USB drive instead of your hard drive.
The Windows installer will walk you through choosing a drive to install on and entering your product key if you have one.
After installation completes, remove the USB drive and let Windows finish setting up on your computer.

Download Windows and the Media Creation Tool

Go to Microsoft's Windows download page on a computer that already works. You're looking for the "Windows [version] Installation Media" section — the version number depends on whether you want Windows 11, Windows 10, or an older version. Click the button to download the Media Creation Tool, which is a small program that prepares your USB drive.

Save this file somewhere you'll find it, like your Desktop or Downloads folder. The download is usually 20 to 30 MB and takes a few minutes on a normal internet connection. Once it finishes, you have everything you need to prepare the USB drive.

Prepare the USB drive with Media Creation Tool

Plug your USB drive into the computer where you downloaded the Media Creation Tool. Open the Media Creation Tool file you just downloaded — it will ask for permission to make changes to your computer, which is normal. Click "Yes" or "Accept" when it asks.

The tool will show you two options: "Upgrade this PC now" or "Create installation media for another PC." Choose the second option, "Create installation media for another PC." This prepares the USB drive to install Windows on a different computer.

The tool will ask you to choose a language, edition, and architecture. For most people, the defaults are correct — Windows 11 Home, English, and 64-bit. If you know you need a different edition or language, change it here. Then click "Next."

When it asks what media you want to use, select "USB flash drive," then click "Next." The tool will show you a list of USB drives connected to your computer. Select the one you plugged in — it will show the drive name and size. Click "Next," and the tool will erase the drive and copy Windows onto it. This takes 10 to 20 minutes. When it finishes, you can unplug the USB drive.

Change your computer's boot order

Plug the USB drive into the computer where you want to install Windows. Restart that computer completely — don't just put it to sleep. As soon as it starts turning back on, you need to enter the boot menu or BIOS setup. The key to press is different on almost every computer: common ones are F2, F12, Delete, or Escape. It usually appears on the screen for just a second as the computer starts, so watch carefully.

If you miss it, restart again and try the same key. If nothing happens, try a different key from the list above. Once you're in the boot menu or BIOS, look for an option that says "Boot Order," "Boot Sequence," or "Boot Device." You want to move the USB drive to the top of the list so the computer starts from it instead of your hard drive.

The exact steps depend on your computer's BIOS, but usually you can use arrow keys to highlight the USB drive and then press Enter or use + and - keys to move it up. Once the USB drive is first, save your changes — usually by pressing F10 or looking for a "Save and Exit" button. The computer will restart.

Run the Windows installer

After you change the boot order and save, your computer will restart from the USB drive. You'll see a black screen with white text saying "Press any key to boot from CD or DVD." Press any key on your keyboard. The Windows installer will load — this takes a minute or two.

The installer will ask you to choose a language, time zone, and keyboard layout. The defaults are usually correct. Click "Next," then click "Install Now." If you have a product key, you can enter it here, but you can also skip this and enter it later — click "I don't have a product key" if you want to continue without one.

The installer will ask which version of Windows you want — usually Home or Pro. Choose the one that matches your product key, or pick Home if you don't have a key. Then it will ask you where to install Windows. You'll see a list of hard drives and partitions on your computer. Select the drive where you want Windows installed, then click "Next." The installer will warn you that it's about to erase that drive — click "OK" to continue.

Wait for installation to finish

The installer will copy files to your hard drive and install Windows. This takes 15 to 45 minutes depending on your computer's speed. You'll see a progress bar and a spinning circle. Don't turn off your computer or unplug anything during this time.

Your computer may restart several times during installation — this is normal. Each time it restarts, it will continue the installation automatically. You don't need to press any keys or do anything. Just wait.

When installation finishes, your computer will restart one more time. Remove the USB drive before it finishes restarting, so it boots from your hard drive instead. Windows will then load for the first time and ask you to set up your user account, choose privacy settings, and connect to the internet. Follow the on-screen instructions to finish.

Troubleshooting if something goes wrong

If your computer doesn't boot from the USB drive, you probably didn't enter the boot menu correctly. Restart again and watch the screen more carefully as it starts — the key to press usually appears in the bottom corner for just a second. Common keys are F2, F12, Delete, and Escape. If you're not sure, try restarting and pressing F12 first, as that works on many computers.

If the installer says "No drives found," your hard drive may not be recognized. This usually means you need a driver for your hard drive controller, which is rare on newer computers. If this happens, you may need to contact the computer manufacturer or try a different USB drive.

If Windows starts installing but then stops with an error, the USB drive may be corrupted. Unplug it, go back to a working computer, and run the Media Creation Tool again to prepare a fresh USB drive. Make sure you're using a different USB drive if possible, in case the first one is faulty.

Frequently Asked Questions

Do I need a product key to install Windows?

No. You can skip entering a product key during installation and install Windows without one. Windows will ask you to enter a key later, and you can do that anytime. If you don't have a key, Windows will still work, but you may see a watermark on your desktop reminding you to activate it.

Can I use the same USB drive to install Windows on multiple computers?

Yes. Once you prepare the USB drive with the Media Creation Tool, you can use it to install Windows on as many computers as you want. You don't need to prepare it again unless you want to change the Windows version or language.

What if I don't know which hard drive to select during installation?

If you only have one hard drive, select that one. If you have multiple drives and aren't sure which one to use, look at the size — your main drive is usually the largest one. You can also unplug extra drives before installation if you're worried about selecting the wrong one, then plug them back in after Windows is installed.

Will installing Windows erase my files?

Yes, installing Windows on a drive will erase everything on that drive. If you have files you want to keep, back them up to an external drive or cloud storage before you start. If you're installing Windows on a new hard drive, your old drive will stay intact.

How do I know if my computer is 32-bit or 64-bit?

Most computers made in the last 10 years are 64-bit. If you're not sure, use 64-bit — it works on almost all modern computers. If installation fails, you can try again with 32-bit, but this is rarely necessary.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.