Your product key is usually in an email from Microsoft, on a sticker on your device, or buried in Windows settings — the location depends on how you bought Windows.
If you bought Windows 10 as a standalone product, the key came in an email or on a card in the box. If your computer came with Windows pre-installed, the key is embedded in the hardware and you can retrieve it from Windows itself. If you upgraded from Windows 7 or 8, the key may be tied to your Microsoft account instead of being a traditional 25-character code. The method you use to find it depends on which of these situations matches yours.
Key Takeaways
- Check your email first if you bought Windows 10 directly from Microsoft — the product key arrives in a confirmation message.
- Look for a sticker on the back or bottom of your device if Windows came pre-installed, usually labeled "Windows" with a 25-character code.
- Open Settings and go to System > About to find your product key if it is embedded in your hardware by the manufacturer.
- Use a command-line tool or third-party software to extract your product key from Windows if you cannot find it physically or in email.
- If you upgraded from an older Windows version, your key may be linked to your Microsoft account rather than being a separate code.
Check your email and purchase receipts first
When you buy Windows 10 directly from Microsoft or an authorized retailer, the product key arrives in a confirmation email. Search your email inbox for messages from Microsoft, the retailer you used, or any confirmation of a Windows purchase. The subject line usually contains "product key", "license", or "order confirmation". Look in your spam and promotions folders too — these emails sometimes get filtered away.
If you bought Windows through a retailer like Amazon, Best Buy, or Newegg, check your account on that site. Log in, find your order history, and look for the Windows 10 purchase. Many retailers display the product key in your account dashboard or send it in a separate email after the order ships. If you have a physical receipt or the original packaging, the key may be printed there as well.
Look for a sticker on your device
If your computer came with Windows 10 pre-installed by the manufacturer — Dell, HP, Lenovo, Asus, or another brand — the product key is usually on a sticker attached to the device. Check the back of the laptop, the bottom of the tower, or sometimes on the inside of the battery compartment. The sticker is typically white or silver and labeled "Windows" or "Certificate of Authenticity". The product key is a 25-character code in the format XXXXX-XXXXX-XXXXX-XXXXX-XXXXX.
Take a photo of the sticker with your phone if you find it. The sticker can wear off or become hard to read over time, so having a photo backup is useful. If the sticker is missing or illegible, move to the next method — you can still retrieve your key from Windows itself.
Extract your product key from Windows settings
If your key is embedded in your hardware by the manufacturer, you can find it in Windows without looking for a physical sticker. Open Settings by pressing Windows key + I, then go to System and select About. Scroll down to find "Windows specifications". Look for a field labeled "Product ID" or "Product Key" — this is not always visible in the standard Settings view, so you may need to use a command-line tool instead.
Open Command Prompt as an administrator. Press Windows key + R, type cmd, and press Enter. At the command prompt, type the following command exactly:
wmic os get serialnumber
This returns your system's serial number, which is different from your product key but can help you contact the manufacturer if needed. For the actual product key, you will need to use a third-party tool or contact Microsoft support with your device serial number.
Use a third-party tool to retrieve your key
If you cannot find your product key through the methods above, you can use free software to extract it from your Windows installation. ProduKey by Nirsoft is a common choice — it reads the product key directly from your Windows registry and displays it on screen. read it from the Nirsoft website, run the executable file, and it will show your Windows product key when ready. No installation is required.
Another option is Belarc Advisor, which scans your entire system and generates a detailed report including your Windows product key, installed software, and hardware details. read it, run the installer, and let it complete its scan. The report opens in your browser and includes your product key in the Windows section.
These tools work because your product key is stored in the Windows registry on your computer. They straightforward read and display what is already there. They do not modify anything or require internet access to work.
What to do if you upgraded from Windows 7 or 8
If you upgraded to Windows 10 from an older version of Windows, your situation is different. Microsoft tied many upgrades to a Microsoft account rather than issuing a separate product key. When you upgraded, Windows 10 became activated on your device and linked to your account.
To check if your key is tied to your account, sign in to your Microsoft account at account.microsoft.com and look for a "Devices" or "Licenses" section. You should see Windows 10 listed as activated on your device. If you need to reinstall Windows 10 on the same device, you can do so without entering a product key — Windows will recognize your device and set up automatically when you sign in with the same Microsoft account.
If you want to move Windows 10 to a different device, contact Microsoft support. Upgrades from older Windows versions have different transfer rules than retail licenses, and support can help you understand what is allowed.
Contact Microsoft if you still cannot find your key
If you have tried all the methods above and still cannot locate your product key, contact Microsoft support. Have ready the email address associated with your Microsoft account, your device serial number (found in Settings > System > About), and any proof of purchase you have. Microsoft can look up your account and may be able to provide your product key or help you reactivate Windows.
You can reach Microsoft support through their website at support.microsoft.com. Choose "Windows" as the product, then "Windows 10", and select "set up" as the issue. You will be offered options to chat with support, schedule a call, or browse articles. Response times vary, but chat support is usually available during business hours.
Frequently Asked Questions
Can I use the same product key on multiple computers?
No. A Windows 10 product key is licensed for one device only. If you try to set up the same key on a second computer, the first one will lose set up. If you need Windows on multiple devices, you need a separate key for each one.
What if my product key does not work when I try to set up Windows?
The key may have been used already, entered incorrectly, or tied to a different device. Double-check that you typed it correctly — product keys are case-insensitive, but hyphens must be in the right places. If it still does not work, contact Microsoft support with proof of purchase.
Do I need my product key to reinstall Windows 10?
Not always. If Windows 10 is already activated on your device, you can reinstall it without entering a key — Windows will reactivate automatically. If you are installing on a different device, you will need the product key or a Microsoft account that has the license tied to it.
Is my product key the same as my Windows license?
The product key is proof of your license, but they are not the same thing. Your license is the right to use Windows; the product key is the code that proves you own that right. Some licenses, especially from upgrades, are tied to your account instead of a physical key.
What should I do with my product key once I find it?
Write it down or take a photo and store it somewhere safe — a password manager, a find note, or a physical notebook. You may need it if you reinstall Windows, troubleshoot set up problems, or contact support. Do not share it publicly or post it online.