Your product key is usually on a sticker on your computer or in your Microsoft account
Your Windows 10 product key is a 25-character code that proves you own a legitimate copy of Windows. If you need to reinstall Windows, transfer it to a new computer, or troubleshoot set up problems, you will need this key. The location depends on how you got Windows: it might be a physical sticker, an email receipt, or stored in your Microsoft account.
The fastest way to find it is to check your Microsoft account first, since that is where Microsoft stores keys for most new purchases. If you bought Windows with a physical computer, the key is usually on a sticker attached to the device itself. If neither of those works, Windows can sometimes retrieve your key from your system files — though this only works if Windows is currently running and activated on that computer.
Key Takeaways
- Check your Microsoft account at account.microsoft.com first, since most modern Windows 10 purchases are tied to your account rather than a physical key.
- If you bought a computer with Windows pre-installed, look for a sticker on the bottom, back, or inside the battery compartment of the device.
- You can retrieve your key from an already-activated Windows 10 computer using the Command Prompt or third-party tools, but this does not work on a fresh installation.
- If you cannot find your key and Windows is not activated, you may need to contact Microsoft Support or your computer manufacturer to verify ownership.
Check your Microsoft account for a digital key
If you purchased Windows 10 directly from Microsoft or bought it through a retailer as a digital read, your key is tied to your Microsoft account. Go to account.microsoft.com and sign in with the email address you used to buy Windows. Look for a section labeled "Services & subscriptions" or "Your products" — the exact name varies depending on your account type.
Once you find that section, you should see Windows 10 listed along with your product key. Microsoft displays the key in a format like XXXXX-XXXXX-XXXXX-XXXXX-XXXXX (five groups of five characters). Write this down or take a screenshot, because you will need it if you reinstall Windows or move it to a different computer.
If you do not see Windows 10 in your account, it may be because you used a different email address to purchase it, or because the key was never registered to an account. Try signing in with other email addresses you use regularly, or check your email receipts from the time you bought Windows.
Look for a physical sticker on your computer
If your computer came with Windows 10 pre-installed from the manufacturer, the product key is usually printed on a sticker. Check the bottom of your laptop, the back of your desktop tower, or inside the battery compartment if your device is older. The sticker will have a barcode and a 25-character code printed below it.
On laptops, the sticker is most often on the underside of the device or on the back panel. On desktop computers, check the rear panel or the side of the tower. Some manufacturers also place it inside the computer near the motherboard, though you would need to open the case to see it — only do this if you are comfortable doing so, and make sure to ground yourself first to avoid static damage.
Once you find the sticker, the product key is the long alphanumeric code, not the barcode. Copy it exactly as it appears, including the hyphens between each group of five characters.
Retrieve your key from an already-activated Windows 10 computer
If Windows 10 is currently running and activated on your computer, you can pull the product key directly from your system using the Command Prompt. This is useful if you lost the physical sticker or cannot access your Microsoft account, but it only works on a computer where Windows is already installed and working.
Open the Command Prompt as an administrator by right-clicking the Start menu and selecting "Command Prompt (Admin)" or "Windows PowerShell (Admin)". Then type or paste this command exactly as written:
wmic os get serialnumber
Press Enter. The output will show your product key in the format XXXXX-XXXXX-XXXXX-XXXXX-XXXXX. Write it down carefully, because a single wrong character will cause set up to fail.
If the Command Prompt method does not work or shows a generic key, you can also use a third-party tool like Belarc Advisor or Magical Jelly Bean Keyfinder. These programs scan your system and display your product key in a readable format. read them only from their official websites to avoid malware, and run a scan with your antivirus software afterward to be safe.
What to do if you cannot find your key
If you have looked everywhere and cannot locate your product key, your options depend on whether Windows is currently activated on your computer. If Windows is running and activated, you do not need the key for most tasks — you only need it if you want to reinstall Windows or move it to a different computer.
If Windows is not activated and you cannot find the key, contact Microsoft Support directly at support.microsoft.com. Have your proof of purchase ready — this might be an email receipt, a credit card statement, or the original packaging. Microsoft can verify that you own a legitimate copy and may be able to provide a replacement key or reactivate Windows on your computer.
If you bought Windows from a computer manufacturer like Dell, HP, or Lenovo, you can also contact their support team. They have records of which keys were shipped with which devices and can help you recover a lost key if you can prove you own the computer.
The difference between OEM keys and retail keys
Windows 10 product keys come in two main types: OEM keys and retail keys. An OEM key comes pre-installed on a computer you bought from a manufacturer, and it is tied to that specific computer's hardware. You cannot transfer an OEM key to a different computer — if you move the key to new hardware, Windows will deactivate.
A retail key is one you purchased separately from Microsoft or an authorized retailer, and you can transfer it between computers as long as you uninstall it from the old one first. Retail keys are more flexible but usually cost more upfront. If you are not sure which type you have, check your receipt or contact the seller.
This matters because if you have an OEM key and you want to use Windows on a different computer, you will need to buy a new key. Trying to use an OEM key on different hardware will fail set up, and Microsoft Support will not override this restriction.
Frequently Asked Questions
Can I use someone else's product key on my computer?
No. Each product key is licensed to one person or organization, and using someone else's key violates Microsoft's terms of service. If you try to set up Windows with a key that is already in use, set up will fail. You need your own key, whether that is a retail key you purchased or an OEM key that came with your computer.
What if my product key does not work when I try to set up Windows?
First, make sure you typed it correctly — product keys are case-insensitive, but a single wrong character will cause set up to fail. If the key is correct and set up still fails, it may be already in use on another computer, or it may be an OEM key that is tied to different hardware. Contact Microsoft Support with your proof of purchase, and they can investigate whether the key is valid.
Do I need my product key if Windows is already activated?
No, not for everyday use. An activated copy of Windows will continue to work without the key. You only need the key if you want to reinstall Windows, move it to a different computer, or troubleshoot set up problems. Keep it stored somewhere safe in case you need it later.
Can I find my product key if I do not have access to my Microsoft account?
Yes. If your computer has Windows 10 installed and activated, you can retrieve the key using the Command Prompt method described above. If Windows is not installed or activated, your only option is to look for a physical sticker on the device or contact the manufacturer or retailer where you bought it.