Installing Windows From a USB Drive: A Step-by-Step Process

What you need before you start

Installing Windows from USB means you are writing the Windows installation files onto a USB drive, then booting your computer from that drive to install or reinstall the operating system. You will need a USB drive with at least 8 gigabytes of storage space (16 gigabytes is safer), a computer that can connect to the internet, and access to another working computer if the one you are installing on will not start.

The process has three stages: creating the installation USB on a working computer, inserting that USB into the target computer, and walking through the Windows setup screens. Most people get stuck because they do not know how to change the boot order in their computer's startup settings, or because their USB drive was not written correctly the first time.

You will also need a Windows product key or license. If you are reinstalling Windows on a computer that already had it, your license is usually tied to your hardware and will reactivate automatically. If you are installing on a new computer or a blank drive, you will need to purchase a license or use the free evaluation version (which works fully but displays a watermark).

Key Takeaways

You create the installation USB on a working computer using the Windows Media Creation Tool, which is free from Microsoft and handles all the file writing for you.
The USB drive must be at least 8 gigabytes and will be completely erased during the process, so back up anything on it first.
After plugging the USB into your target computer, you must enter the boot menu (usually by pressing Delete, F2, F10, or F12 during startup) and select the USB drive as the first boot device.
Windows setup will ask you to choose a drive to install on; if you are replacing an existing installation, select the drive that currently holds Windows and it will be overwritten.
The installation takes 15 to 45 minutes depending on your computer's speed, and your computer will restart several times during the process.

Creating the installation USB on a working computer

Go to the Microsoft Windows read page on a computer that is already working and has internet access. Look for the section labeled "Create Windows installation media" and read the Windows Media Creation Tool. This is a small program (about 20 megabytes) that will guide you through building your installation USB.

Plug in your USB drive. Open the Media Creation Tool you just downloaded. It will ask whether you want to upgrade this computer or create installation media for another computer — choose "Create installation media for another PC." The tool will then ask you to select the language, edition (Home or Pro), and architecture (64-bit or 32-bit). If you do not know which edition or architecture your target computer uses, 64-bit Windows 10 or Windows 11 Home is the most common choice. The tool will read the Windows files (this takes 10 to 30 minutes depending on your internet speed) and write them to your USB drive, erasing anything already on it.

When the tool finishes, eject the USB drive safely by right-clicking it in File Explorer and selecting "Eject." Do not just pull it out. The USB is now ready to use on any computer.

Entering the boot menu on your target computer

Shut down the computer where you want to install Windows completely. Plug in the USB drive. Turn the computer back on and when ready start pressing a specific key repeatedly — the key depends on your computer's manufacturer. Common keys are Delete, F2, F10, or F12. You are trying to enter the BIOS or UEFI settings screen, which looks different from the normal Windows startup. If you see the Windows logo or the login screen, you waited too long; shut down and try again, pressing the key faster.

Once you are in the BIOS or UEFI screen, look for a section called "Boot Order," "Boot Sequence," or "Boot Priority." You should see your USB drive listed by name (it might say "USB Device" or show the drive manufacturer). Use the arrow keys to move the USB drive to the top of the list so it boots first. Save your changes (usually by pressing F10 or selecting "Save and Exit") and the computer will restart.

If you cannot find the boot menu, restart the computer and try a different key. If none of the common keys work, search online for "[your computer model] boot menu key" — manufacturers sometimes use unusual keys. Some newer computers with Windows 11 have a different process: you may need to restart into Windows settings, go to System > Recovery > Advanced Startup, and choose to boot from USB from there instead.

Walking through Windows setup

After you save your boot settings, the computer will restart and load Windows setup from the USB drive. You will see a screen asking you to choose your language, time zone, and keyboard layout. Select the options that match your location and click "Next."

The next screen will ask you to enter your Windows product key. If you have one, type it in. If you do not have a key yet, click "I do not have a product key" — you can enter it later or use Windows with the evaluation watermark. Click "Next."

Windows will then ask you which drive to install on. If your computer has only one drive, it will be listed as "Drive 0" or with the drive manufacturer's name. If you are replacing an existing Windows installation, select that drive and click "Next" — Windows will warn you that everything on it will be deleted, which is what you want. If you are installing on a new blank drive or a second drive, select that one instead. Do not select a drive you want to keep.

Windows will now copy files and install itself. This takes 15 to 45 minutes. Your computer will restart several times — this is normal and expected. Do not unplug the USB drive or turn off the computer during this time. When setup finishes, you will see the Windows login screen or a setup screen asking for your Microsoft account information.

What to do if setup fails or gets stuck

If Windows setup stops responding or shows an error message, the most common cause is that the USB drive was not written correctly. Shut down the computer, go back to your working computer, and run the Media Creation Tool again on the same USB drive. The tool will rewrite it and fix most corruption issues.

If you see an error about "no bootable device found," the USB drive did not get recognized as a boot device. Restart the target computer, enter the boot menu again, and make sure the USB drive is actually listed. If it is not appearing at all, try a different USB port (use a port on the back of the computer if you were using a front port, or vice versa). Some computers have USB ports that do not support booting.

If Windows setup starts but then says the drive is not compatible or cannot be found, the target computer may use a newer storage format that older Windows versions do not recognize. In this case, you may need to create the USB using a newer Windows version (Windows 11 instead of Windows 10), or you may need to change a BIOS setting called "SATA Mode" from RAID to AHCI. Search online for your computer model and "SATA Mode" if you hit this error.

After Windows is installed

Once Windows setup finishes and you see the login screen, you can remove the USB drive. You do not need it anymore. Windows will now boot from your computer's hard drive or solid-state drive as normal.

Your next steps are to install drivers (especially graphics drivers and chipset drivers from your computer manufacturer's website), run Windows Update to get security patches, and restore any files you backed up before the installation. If you did not enter a product key during setup, go to Settings > System > set up and enter it now. Windows will set up online within a few minutes.

Frequently Asked Questions

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

Yes. The USB drive is just a copy of the Windows installation files, so you can use it on as many computers as you want. Each computer will need its own valid Windows license to set up, but the USB itself can be reused indefinitely.

What if my computer does not have a USB port?

Older computers sometimes lack USB ports. You can use a USB adapter that connects to an older port type (like parallel or serial), though these are rare. A more practical solution is to use a different installation method, such as a DVD if your computer has a DVD drive, or taking the computer to a repair shop that can install Windows for you.

Will installing Windows from USB delete my files?

Only if you select the drive containing your files during setup. If your computer has two drives and you install Windows on the second one, your files on the first drive will remain untouched. If you have only one drive and want to keep your files, back them up to an external drive or cloud storage before you start.

Do I need internet during the Windows installation?

No, but you will need it afterward to read drivers and security updates. The installation itself works completely offline from the USB drive.

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

If your computer is currently running Windows, right-click "This PC" or "My Computer," select Properties, and look for "System Type." It will say either "64-bit Operating System" or "32-bit Operating System." If your computer will not start at all, assume 64-bit — it is far more common on computers made in the last ten years.

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.