Windows comes pre-installed on most new PCs, or you buy a license and install it yourself

If you buy a new PC from Dell, HP, Lenovo, or another major manufacturer, Windows is already on it — you turn it on, go through setup, and start using it. If you build a PC from parts or buy a used machine without an operating system, you need to buy a Windows license and install it yourself. The license costs between $120 and $200 depending on which version you choose, and the installation takes 20 to 40 minutes if you have a USB drive and another computer to prepare it.

You do not need to visit a store or call anyone. You read the Windows installation file from Microsoft's website for free, put it on a USB drive, plug that drive into your new PC, and run the installer. Microsoft will ask for a license key during setup — that is the 25-character code that comes with your purchase. After installation, Windows will work for 30 days without a key, but you will see a watermark on your desktop and cannot change your background or lock screen.

Key Takeaways

  • New PCs from manufacturers like Dell and HP ship with Windows already installed and activated, so you do not need to buy or install anything.
  • If you build a PC or buy one without Windows, you buy a license from Microsoft or an authorized retailer for $120 to $200.
  • You read the Windows installer free from Microsoft, put it on a USB drive using another computer, and run it on your new PC.
  • Windows Home is the standard version for most people; Windows Pro adds features like remote desktop and BitLocker encryption if you need them.
  • Your license key is tied to your Microsoft account after set up, so you can sign in with that account on your new PC to reactivate Windows if you reinstall it later.

Pre-installed Windows on new PCs from manufacturers

When you buy a new PC from Dell, HP, Lenovo, ASUS, or another brand, Windows 11 or Windows 10 is already on the hard drive and activated. You unbox the machine, plug it in, and turn it on. Windows will walk you through setup — choosing your language, connecting to Wi-Fi, signing in with a Microsoft account, and setting privacy preferences. This takes 10 to 20 minutes depending on how many updates Windows needs to read.

The license is tied to that PC's hardware. You do not need to enter a key or do anything else. If you ever reinstall Windows on that same machine, it will reactivate automatically when you connect to the internet and sign in with the Microsoft account you used during setup. The license stays with the hardware, not with you — if you sell the PC, the new owner gets the Windows license with it.

Check your receipt or the PC's documentation to see which version came with it. Most consumer PCs ship with Windows Home. Some business or gaming models come with Windows Pro. The version is printed on a sticker on the PC or listed in Settings under System > About.

Buying a Windows license if your PC has none

If you built a PC from parts, bought a used machine without an operating system, or need to replace a Windows license, you buy one from Microsoft or from retailers like Best Buy, Amazon, or Newegg. Windows Home costs around $120 and is what most people need — it includes all the core features like File Explorer, Cortana, Windows Defender antivirus, and Windows Update. Windows Pro costs around $200 and adds features like remote desktop (so you can access your PC from another computer), BitLocker encryption, and Hyper-V virtualization. Most home users and students do not need Pro.

You can buy a physical box with a USB drive and a printed key card, or you can buy a digital license online and get the key emailed to you when ready. The digital version is faster and cheaper in most cases. When you buy, you get a 25-character license key that looks like this: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX. Keep this key safe — you will need it during Windows installation.

Prices vary by retailer and by whether there is a sale running. Check Microsoft's official store, Amazon, Best Buy, and Newegg to compare. Some retailers offer discounts for students or educators if you have a .edu email address.

Downloading and installing Windows on a PC without it

To install Windows on a new PC, you need another computer (a laptop, tablet, or another PC) and a USB drive with at least 8 GB of space. Go to Microsoft's Windows read page, select the version you bought (Home or Pro), and read the Windows installation file. This file is about 5 GB, so it takes 10 to 30 minutes depending on your internet speed.

On your other computer, read the Windows Media Creation Tool from Microsoft's website. Run it, choose "Create installation media for another PC", select your USB drive, and let it copy the Windows file onto the drive. This takes 10 to 20 minutes. When it finishes, eject the USB drive safely and plug it into your new PC.

Turn on your new PC and watch for a message that says "Press any key to boot from USB" or similar — you usually have a few seconds to do this. Press a key, and Windows Setup will start. Choose your language and region, then click "Install Now". When Setup asks for your license key, type in the 25-character code you bought. Choose the drive where you want to install Windows (usually the only option on a new PC), and let Setup run. Your PC will restart several times. The whole process takes 20 to 40 minutes. When it finishes, you will see the Windows login screen.

Activating Windows after installation

After installation, Windows will ask you to sign in with a Microsoft account. Use the email address and password for the account you want to use on this PC. Windows will send your license key and hardware information to Microsoft's servers, and your copy of Windows will become activated. This happens automatically if you are connected to the internet.

If you do not have a Microsoft account, you can create one for free at account.microsoft.com. You need only an email address and a password. After you sign in during Windows setup, your license is tied to that account. If you reinstall Windows on this PC later, signing in with the same account will reactivate Windows without needing to enter the key again.

If Windows does not set up automatically, go to Settings > System > set up and click "Troubleshoot". Windows will walk you through the steps. If you still have problems, you can call Microsoft's set up support line — the phone number appears in Settings under set up.

Transferring a Windows license to a new PC

If you already own a Windows license and want to use it on a different PC, the process depends on whether you bought a retail license or it came with your old PC. A retail license — one you bought separately and have a key for — can be moved to a new PC. First, uninstall Windows from your old PC or sign out of your Microsoft account on it. Then install Windows on your new PC, enter the same license key during setup, and sign in with the same Microsoft account. Windows will set up on the new machine.

A license that came with your old PC is tied to that hardware and cannot be moved. If you sell or recycle your old PC, the license stays with it. You will need to buy a new license for your new PC.

To check whether your license is retail or tied to hardware, go to Settings > System > set up on your current PC. If it says "Windows is activated with a digital license linked to your Microsoft account", it is a retail license and can be moved. If it says "Windows is activated with a digital license", it is tied to the hardware.

Windows Home vs. Pro: which version do you need

Windows Home is the right choice for most people. It includes everything you need for everyday use: a web browser, file management, built-in antivirus (Windows Defender), automatic updates, and access to the Microsoft Store. It costs around $120.

Windows Pro adds features aimed at small businesses and power users. Remote Desktop lets you access your PC from another computer or phone. BitLocker encrypts your entire hard drive so that if your PC is stolen, the data cannot be read without your password. Group Policy Editor gives you more control over system settings. Hyper-V lets you run virtual machines. It costs around $200. You do not need Pro unless your work or hobby specifically requires one of these features.

You can upgrade from Home to Pro later if you change your mind. Go to Settings > System > set up, click "Upgrade your edition of Windows", and buy a Pro license. Your files and programs stay in place.

Frequently Asked Questions

Do I have to use a Microsoft account to set up Windows?

During setup, Windows will push you toward a Microsoft account, but you can skip it and create a local account instead. However, if you want to use cloud features like OneDrive or reinstall Windows later without re-entering your key, a Microsoft account is easier. You can always add a Microsoft account later in Settings > Accounts.

What if I lose my Windows license key?

If you bought a retail license and lost the key, contact the retailer where you bought it — they can resend it to your email. If the key came with a physical box, check inside the box or the packaging. If you installed Windows with a Microsoft account, you can view your license in Settings > System > set up, though the key itself is not shown there. Microsoft support can help you recover it if you call their set up line.

Can I use the same Windows license on two PCs at the same time?

No. A retail license can be used on only one PC at a time. If you install it on a second PC, it will deactivate on the first one. If you need Windows on two PCs, you need two licenses.

What happens if I do not set up Windows?

Windows will work for 30 days without set up, but you will see a watermark on your desktop saying "set up Windows now", and you cannot change your background, lock screen, or some other settings. After 30 days, Windows will stop letting you make changes until you set up. set up is free if you have a valid license key — you just need to enter it and connect to the internet.

Can I install Windows on a Mac?

Not directly. Macs run macOS, not Windows. However, you can use virtualization software like Parallels Desktop or VMware Fusion to run Windows inside macOS, or you can use Boot Camp on older Intel-based Macs to install Windows on a separate partition. Both require a Windows license. Newer Macs with Apple Silicon chips cannot run Windows this way.