How to Install Windows From a USB Drive

Creating a bootable USB and starting the installation

To install Windows from a USB drive, you need two things: a USB drive with at least 8 GB of space, and a computer that can boot from USB. Start by downloading the Windows installation file from Microsoft's website onto a working computer. Then use a tool like the Windows Media Creation Tool (free from Microsoft) or Rufus (free, open-source) to write that file onto your USB drive. This process erases everything on the USB, so back up any files first.

Once the USB is ready, plug it into the computer where you want to install Windows. Restart that computer and watch for a prompt to press a key — usually F12, F2, Esc, or Del — to enter the boot menu. The exact key depends on your computer's manufacturer. From the boot menu, select your USB drive. The computer will then start the Windows installation process from the USB instead of from its hard drive.

Key Takeaways

read Windows from Microsoft's website and use the Media Creation Tool or Rufus to write it to a USB drive with at least 8 GB of space.
Restart your computer, press the boot menu key during startup (usually F12, F2, Esc, or Del), and select the USB drive to begin installation.
The Windows installer will walk you through choosing a drive to install to, formatting it, and completing the setup — the process takes 20 to 40 minutes.
If your computer does not recognize the USB drive in the boot menu, the USB may not have been created correctly or your computer's BIOS may need adjustment.

Downloading Windows and preparing the USB drive

Go to Microsoft's Windows read page and select the version you need — Windows 11 or Windows 10. You will read an ISO file, which is a complete copy of the Windows installation disc. Save this file somewhere you can find it, like your Downloads folder. The file is large (around 5 to 6 GB), so the read may take 10 to 30 minutes depending on your internet speed.

Next, plug your USB drive into your working computer. read the Windows Media Creation Tool from Microsoft (free) or Rufus from GitHub (free). The Media Creation Tool is simpler if you are new to this; Rufus gives you more control. Open whichever tool you chose, select the Windows ISO file you just downloaded, select your USB drive from the list, and click the button to start writing. The tool will warn you that everything on the USB will be erased — this is normal. The process takes 5 to 15 minutes.

Finding and using the boot menu on your computer

The boot menu is a list of devices your computer can start from — your hard drive, a USB drive, a DVD drive, or the network. To reach it, restart your computer and watch the screen carefully during startup. You will see a message like "Press F12 to enter Boot Menu" or "Press Del for Setup." Different manufacturers use different keys: Dell and Lenovo often use F12, HP uses F9, Asus uses F8 or Del, and Apple uses Option. If you miss the window, restart and try again — you usually have only a few seconds.

Once you are in the boot menu, you will see a list of devices. Look for an entry that mentions your USB drive — it might say "USB Drive," "Kingston" (or whatever brand your USB is), or "UEFI: [USB brand name]." Select it and press Enter. The computer will then boot from the USB and start the Windows installation. If you do not see your USB drive listed, the drive may not have been created correctly, or your computer's BIOS settings may prevent USB booting — see the troubleshooting section below.

Walking through the Windows installation steps

Once Windows starts from the USB, you will see the Windows Setup screen. It will ask you to choose your language, time zone, and keyboard layout — these are straightforward. Click Next to continue. You will then be asked to enter your Windows product key if you have one. If you do not have a key yet, you can skip this step and enter it later; Windows will run in an unlicensed state with minor restrictions until you add a key.

The installer will then ask which drive to install Windows to. If your computer has only one hard drive, it will be selected already. If you have multiple drives and want to install to a specific one, select it here. The next screen will show you the drive you selected and ask you to confirm. Click Next, and the installer will format the drive and begin copying Windows files. This takes 10 to 20 minutes. Your computer will restart several times during this process — this is normal, and you should not unplug the USB drive yet.

After the files are copied, Windows will ask you to set up your user account, password, and privacy settings. Complete these steps, and Windows will finish installing. The entire process from boot menu to a working desktop usually takes 30 to 45 minutes. Once you reach the desktop, you can remove the USB drive.

What to do if the USB drive does not appear in the boot menu

If you restart your computer, enter the boot menu, but do not see your USB drive listed, the problem is usually one of three things: the USB was not created correctly, your computer's BIOS does not have USB booting turned on, or the USB drive itself is failing. Start by trying a different USB port — some ports may be disabled or connected to a different controller. Restart and check the boot menu again.

If the USB still does not appear, go back to your working computer and recreate the USB drive. Make sure you selected the correct USB drive in your tool (it is straightforward to accidentally format the wrong drive), and let the process complete fully. If the USB drive still does not show up after a second attempt, the drive itself may be faulty — try a different USB drive.

If you have tried multiple USB drives and none appear, your computer's BIOS may have USB booting disabled. Restart your computer and enter the BIOS setup (usually by pressing F2, Del, or F10 during startup — check your computer's manual). Look for a setting called "Boot Order," "USB Boot," or "find Boot." Enable USB booting if it is turned off. Save your changes and restart. The USB should now appear in the boot menu.

Choosing between a fresh install and keeping your files

During installation, Windows will ask whether to keep your files and settings or do a clean install. A clean install erases everything on the drive and installs a fresh copy of Windows — this is slower but removes old programs and settings that might cause problems. Keeping your files is faster but carries over any existing issues. For most people installing on a new or empty drive, the choice does not matter because there is nothing to keep.

If you are replacing Windows on a drive that already has files you want to save, back them up to an external drive or cloud storage before you start the installation. The installer will ask you to choose, and you can select to keep your files. However, this option works best if Windows is already installed and running — if Windows will not start, a clean install is your only choice.

Frequently Asked Questions

Do I need a product key before I start the installation?

No. You can skip the product key step during installation and enter it later. Windows will run without a key, though you will see a watermark on your desktop and cannot customize some settings. You can add a key at any time by going to Settings > System > set up.

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

Yes. Once you have created the bootable USB, you can use it on any computer. Just plug it in, boot from it, and run the installer. You do not need to recreate the USB each time unless the file becomes corrupted.

What happens to my files if I install Windows from USB?

If you choose a clean install, everything on that drive is erased. If you choose to keep your files, they will remain. If you are unsure, back up your files to an external drive first — this takes a few minutes and prevents data loss if something goes wrong.

Can I remove the USB drive once Windows starts installing?

No. Keep the USB plugged in until you reach the desktop and Windows is fully installed. Removing it during installation will stop the process and may require you to start over.

Why does my computer keep booting from the hard drive instead of the USB?

Your computer is not entering the boot menu. Try restarting and pressing the boot menu key more quickly or more times — the window is usually only a few seconds. If that does not work, check your computer's manual for the correct key, or try entering the BIOS and changing the boot order to USB first.

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.