How to Install Windows on a New PC

What You Need Before You Start

Installing Windows on a new PC requires three things: a Windows installation file (usually on a USB drive), a product key or digital license, and a second computer to create the installation media if your new PC doesn't have one yet. Most new PCs come with Windows already installed, but if you're building from parts, replacing a drive, or working with a blank machine, you'll need to do this yourself.

The installation process takes 20 to 45 minutes depending on your drive speed and internet connection. You'll need the Windows installation media — either a bootable USB drive or DVD — and your product key, which is a 25-character code that proves you own a license. If you're upgrading from an older Windows version, you may be able to use your existing key, but Windows 11 and Windows 10 have different requirements.

Before you begin, back up any files on the drive you're installing to, because the installation will erase everything on it. Shut down the PC completely and make sure you have a stable power source — a power loss during installation can corrupt the drive.

Key Takeaways

You need a bootable USB drive with Windows installation files, which you create on another computer using the Windows Media Creation Tool.
Your product key is a 25-character code that comes with your Windows license and is required during setup; without it, Windows will install but stop working after 30 days.
Insert the USB drive, restart the PC, and press the boot menu key (usually F12, Del, or Esc) during startup to boot from the USB instead of the hard drive.
The installer will ask you to choose a drive and partition, format it, and copy files — this takes 20 to 45 minutes and the PC will restart several times.
After installation finishes, Windows will ask for your product key and guide you through initial setup, which includes creating a user account and connecting to the internet.

Creating a Bootable Windows Installation USB Drive

You need a second computer and a USB drive with at least 8 GB of storage to create the installation media. Go to the Microsoft Windows read page and select "read Now" under Windows Media Creation Tool. Run the installer on the working computer and choose "Create installation media for another PC."

Select your language, Windows edition (usually Windows 11 Home or Pro), and architecture (64-bit for almost all modern PCs). Choose USB flash drive as your media type, then select your USB drive from the list. The tool will read the Windows files — this takes 10 to 20 minutes depending on your internet speed — and write them to the USB drive. When it finishes, eject the USB safely and take it to your new PC.

If you already have a Windows product key but no installation media, you can use this same process. The key is entered during setup, not before, so you don't need it to create the USB drive.

Booting From the USB Drive and Starting Setup

Insert the USB drive into a USB 3.0 port (the blue ports, usually on the back of the PC) on your new computer. Power on the PC and when ready start pressing the boot menu key — this is usually F12, Delete, Esc, or F2, depending on your motherboard manufacturer. You'll see a brief splash screen with the manufacturer's logo; the correct key is usually listed there. If you miss it, restart and try again.

A menu will appear listing your boot options. Select your USB drive — it may be labeled as "USB Device," "UEFI: [USB brand name]," or similar. The PC will boot from the USB and load the Windows Setup screen within 30 seconds to 2 minutes.

If the boot menu doesn't appear, restart the PC and try a different key. If no menu appears at all, the USB drive may not be bootable — go back to the second computer and recreate it using the Media Creation Tool. Make sure you're using a USB 3.0 port, not a USB 2.0 port, as older ports are slower and sometimes unreliable for installation.

Choosing Your Drive and Partitioning

Windows Setup will ask you to select a language, time zone, and keyboard layout. Accept the defaults unless you need something different. On the next screen, click "Install Now" to begin the installation process.

You'll be asked to enter your product key. If you don't have one yet, you can skip this step — Windows will install and run for 30 days without a key, giving you time to purchase one. After 30 days, you'll see a watermark on your desktop and some features will stop working, but you can enter a key at any time to set up.

Next, you'll see a list of drives on your PC. If this is a brand-new build with one empty drive, you'll see one entry. Select it and click "Next." Windows will automatically create the partitions it needs — you don't need to do this manually. If you have multiple drives and want to choose which one gets Windows, select the correct one here. The installer will format the drive, erasing anything on it.

Waiting for Files to Copy and System Restarts

Once you've selected your drive, Windows begins copying files. This takes 10 to 20 minutes. The screen will show a progress bar and a percentage. Do not interrupt this process — leave the PC alone and don't unplug it.

The PC will restart automatically several times during installation. This is normal. You may see a black screen with "Windows is loading files" or a spinning circle. Each restart takes 2 to 5 minutes. If the PC restarts more than five times or gets stuck on one screen for more than 10 minutes, there may be a problem with the USB drive or the drive you're installing to — restart and try creating the installation media again.

Leave the USB drive plugged in during all restarts. Windows Setup will automatically boot from it again if needed. Once the file copy is complete, the PC will restart one final time and boot into Windows for the first time.

Entering Your Product Key and Completing Setup

After the final restart, Windows will ask you to enter your product key. This is the 25-character code that came with your Windows license. Type it carefully — hyphens are included automatically. If you don't have a key, click "I don't have a product key" and continue. You can add it later through Settings.

Next, you'll choose your region and keyboard layout, then connect to the internet. Windows will read drivers and updates — this takes 5 to 15 minutes depending on your connection speed. Don't skip this step, as drivers are essential for your hardware to work properly.

You'll be asked to create a user account with a username and password. Use a password you'll remember, or write it down somewhere safe. You can also set up a PIN or Windows Hello (fingerprint or face recognition) if your PC has the hardware for it. Once you've created your account, Windows will finish setup and take you to the desktop.

What to Do After Installation Is Complete

Once you're at the desktop, eject the USB drive and store it safely — you may need it again if you ever reinstall Windows. Windows will continue downloading updates in the background for the next hour or so. You can use your PC during this time, but it may be slower than usual.

Check your device manager to make sure all your hardware is recognized. Right-click the Start button, select "Device Manager," and look for any devices with a yellow warning triangle. If you see any, you may need to read drivers from your motherboard or component manufacturer's website. Most modern hardware works without extra drivers, but some components — especially network adapters and graphics cards — may need them.

If you skipped entering a product key during setup, go to Settings, select "System," then "set up" to enter it now. Windows will verify your key online and set up your copy.

Common Problems and How to Fix Them

The PC won't boot from the USB drive. Restart the PC and try a different boot menu key. If that doesn't work, the USB drive may not be bootable. Go back to your second computer, reformat the USB drive, and recreate the installation media using the Media Creation Tool. Make sure you're using a USB 3.0 port on your new PC.

Setup gets stuck on a black screen or spinning circle. Wait 10 minutes — sometimes this is normal and the PC is just copying files slowly. If nothing changes after 10 minutes, force a restart by holding the power button for 10 seconds, then try again. If it happens repeatedly, the USB drive or hard drive may be faulty. Try creating the installation media on a different USB drive.

Windows installs but won't set up after you enter your product key. Make sure you're connected to the internet — Windows needs to verify your key online. If you're connected and set up still fails, the key may already be in use on another PC, or it may be invalid. Contact Microsoft support with your product key and proof of purchase.

You see a "No bootable device found" error. The PC is not finding the USB drive. Insert the USB drive into a different USB port, restart, and try the boot menu again. If you still see the error, the USB drive may not have been created correctly — recreate it on your second computer.

Frequently Asked Questions

Can I use the same product key on two different PCs?

No. A Windows product key is tied to one PC at a time. If you move the key to a new PC, it will deactivate on the old one. If you try to use the same key on two PCs simultaneously, Windows will show an set up error on one or both of them. You need a separate license for each PC.

What if I don't have a second computer to create the installation USB?

You can purchase a Windows installation USB drive from retailers like Amazon or Best Buy, or you can borrow a computer temporarily to create one. Some computer repair shops will create installation media for a small fee. Once the USB is created, you can use it on as many PCs as you want — the key is what limits it to one PC.

Do I need to remove the old hard drive before installing Windows?

No, but it's safer to do so. If you leave the old drive connected, Windows Setup will show both drives and you can choose which one to install to. If you accidentally select the wrong drive, you'll erase the old one. If you're unsure, disconnect the old drive before starting setup, then reconnect it after Windows is installed.

How long does Windows installation take from start to finish?

Plan for 45 minutes to an hour. The actual file copy takes 10 to 20 minutes, but the PC restarts multiple times, and each restart adds 2 to 5 minutes. Initial setup after installation — creating your account and downloading updates — adds another 15 to 30 minutes. Older hard drives or slower internet connections will take longer.

Can I install Windows without a product key?

Yes. Windows will install and run for 30 days without a key. After 30 days, you'll see a watermark saying "set up Windows" on your desktop, and some features like personalization will be limited. You can enter a key at any time to set up. If you never set up, Windows will continue to work, but you won't receive certain updates and the watermark will remain.

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.