A Windows 10 license (often called a product key) proves your copy of Windows is genuine and unlocks full activation, which removes the “Activate Windows” watermark and enables personalization settings. Many people already have a license without realizing it, because most PCs come with Windows activated through a digital license. This guide explains how to check whether you already have one, how to find an existing key, and your options for getting a new license.
Important: Windows 10 Support Has Ended
Microsoft ended support for Windows 10 on October 14, 2025. Windows 10 still runs and can still be activated, but it no longer receives regular security updates unless you’re enrolled in Microsoft’s Extended Security Updates program. If your PC supports it, upgrading to Windows 11 is worth considering before you spend money on a Windows 10 license.
Step 1: Check Whether Windows 10 Is Already Activated
- Press Windows + I to open Settings.
- Go to Update & Security > Activation.
- Read the status:
- “Windows is activated with a digital license” means you’re set; no key is needed.
- “…with a digital license linked to your Microsoft account” means you can reactivate after hardware changes by signing in.
- “Windows is not activated” means you need a valid license.
Step 2: Find a Key You Already Have
Microsoft notes that in most cases Windows 10 and 11 activate automatically with a digital license and don’t need a product key. If you do need one, check these places:
- Purchase confirmation email: If you bought Windows online, the key is usually in the email receipt or your account’s order history.
- The box or card: Retail copies include the key on a label or card inside the packaging.
- Your PC’s firmware: Many PCs that came with Windows have the key stored in the BIOS/UEFI. Windows reads it automatically during reinstallation.
- Command line: You can try to read the firmware key with a command. See how to find your Windows 10 product key using CMD.
Microsoft says it doesn’t keep a record of purchased product keys, so keep your receipts. For more ways to look, see how to find your Windows product key.
Step 3: Get a New License If You Need One
Upgrade to Windows 11
If your PC meets Windows 11’s requirements and Windows 10 is already activated, the upgrade to Windows 11 is free and keeps your activation. Check Settings > Update & Security > Windows Update for the offer.
Buy from Microsoft or an authorized retailer
Microsoft stopped selling Windows 10 directly on its website in early 2023 and now sells Windows 11. Windows 11 licenses can also be purchased from authorized retailers. Some retailers may still sell remaining Windows 10 retail stock. If you need to activate an unactivated Windows 10 installation, the Go to the Store link on the Activation page shows what’s currently available for your PC.
Through work or school
Many organizations provide Windows licenses through volume licensing. Ask your IT department instead of buying one yourself.
Step 4: Enter the Product Key
- Go to Settings > Update & Security > Activation.
- Click Change product key.
- Type the 25-character key and click Next, then Activate.
You can also activate from Command Prompt. See how to activate Windows 10 using CMD.
Avoid Cheap “Key” Sellers
Websites and marketplaces offering Windows keys for a few dollars often sell keys that are resold, intended for volume licensing, or later blocked. A key that works today may stop working after an update or hardware change, and you may have no way to get your money back. Buy from Microsoft or well-known authorized retailers.
If Activation Fails
- Run the Troubleshoot option on the Activation page.
- Make sure the key matches your edition: a Windows 10 Home key won’t activate Windows 10 Pro, and vice versa.
- After major hardware changes, such as a new motherboard, sign in with the Microsoft account linked to your digital license and use the troubleshooter’s “I changed hardware on this device recently” option.
Frequently Asked Questions
Can I use Windows 10 without activating it?
Yes, but you’ll see a watermark and can’t change personalization settings like the wallpaper and colors. See how to get rid of “Activate Windows”.
Does a license transfer to a new PC?
Retail licenses can generally be moved to a new PC (after removing them from the old one). OEM licenses that came preinstalled are usually tied to the original computer.
Summary
To get a Windows 10 license key, first check Settings > Update & Security > Activation, since many PCs already have a digital license. Look for an existing key in your purchase email, packaging, or PC firmware. If you need a new license, consider upgrading to Windows 11 or buying from Microsoft or an authorized retailer, and avoid unusually cheap keys.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.