You can check if a Windows key is genuine in three stages: look at the activation status, find out the license type, and confirm where the key came from. The status is shown on the Settings → System → Activation page. But Microsoft says plainly that activation only pairs a key or digital license with your hardware and doesn’t guarantee the copy is genuine, so you also need to check where you bought it.
This guide covers Windows 11, with the differences for Windows 10 noted separately. The commands in it only display license information and don’t change anything on your system. Microsoft’s help pages don’t offer a separate service for checking a key in advance: the key is verified during activation.
Open the Activation page
Press Win + I or select Start → Settings, then go to System → Activation.
On Windows 10, the path is different: Start → Settings → Update & Security → Activation. Windows 10 support ended on October 14, 2025, but checking activation works the same way. If your PC meets the requirements, you can upgrade a genuine copy of Windows 10 to Windows 11 for free and get a digital license.
Result: The Activation page opens, with your Windows edition at the top and the Activation state line below it.
Check the activation status
The status appears next to Activation state (on Windows 10, next to Activation). Here’s what the messages mean:
| Message | What it means |
|---|---|
| Windows is activated | Activated, Microsoft account not linked |
| Windows is activated with a digital license | Activated, license not linked |
| Windows is activated with a digital license linked to your Microsoft account | Activated, license linked |
| Windows is activated using your organization’s activation service | Activated by an organization’s server (KMS) |
| Windows is not activated | Not activated, an error message follows |
A digital license is a way to activate Windows 10 and 11 without entering a key: it’s tied to your PC’s hardware and can be linked to a Microsoft account. A product key is a 25-character code in the format XXXXX-XXXXX-XXXXX-XXXXX-XXXXX. Which one you have depends on how you got Windows, as the table in the last step shows.
Result: You know whether Windows is activated and whether the license is linked to your Microsoft account.
Match your Windows edition to your license
Your edition, such as Windows 11 Home or Windows 11 Pro, is shown at the top of the same page (on Windows 10, in the Edition line). The license must match it: if the edition differs from the one you bought, Windows won’t activate. A Home key won’t work for Pro, and vice versa.
If the Activation troubleshooter finds a digital license for a different edition, it suggests a fix. With a Pro license on a PC running Home, it offers to upgrade to Pro; with a Home license on a PC running Pro, you’ll need to reinstall Home.
Result: The edition on the page matches the edition on your license: Home or Pro.
Find out the license type
Press Win + R, type the command, and press Enter. You don’t need administrator rights for it.
slmgr /dliA Windows Script Host window opens. In the Description line, the license channel follows the name of the operating system:
- RETAIL: a retail license from a boxed or digital copy. The Microsoft Store sells these keys too.
- OEM with a suffix, such as OEM_DM: the PC manufacturer’s license the computer was sold with.
- VOLUME_KMSCLIENT or VOLUME_MAK: a volume license, activated through an organization’s server (KMS) or with a Multiple Activation Key (MAK).
The Partial Product Key line shows the last five characters of the installed key. If you entered the key yourself, they should match the end of the key in your email or on your card. On PCs with Windows preinstalled, this line may show a default key instead of the one stored in firmware; Microsoft calls this expected behavior.
A second command shows how long the activation lasts:
slmgr /xprIf the activation is permanent, you’ll see “The machine is permanently activated.” If it shows a date when volume activation will expire, the PC was activated through an organization’s KMS server, and such a client has to contact the server at least once every 180 days.
Microsoft is phasing out VBScript, which slmgr.vbs is written in. On Windows 11 with the September 2026 updates, a PowerShell command also shows license information:
Get-OSLicenseInfo | Select-Object Name, Description, LicenseStatusResult: You know the license channel: retail (RETAIL), PC manufacturer (OEM) or volume (VOLUME).
Check where the key came from
In the end, the source decides whether a key is genuine. Microsoft lists the legitimate ways to get Windows and where to find the key or license in each case:
| How you got Windows | Activation method | Where the key or license is |
|---|---|---|
| Free upgrade from genuine Windows | Digital license | In your Microsoft account, if you signed in |
| Purchase in the Microsoft Store app | Digital license | In the account on the purchase email |
| Purchase on the Microsoft Store website | Product key | Email with your order history |
| New PC with Windows | Product key | On the device, packaging or COA |
| Boxed copy from an authorized retailer | Product key | Label or card inside the box |
| Digital copy from an authorized retailer | Product key | Email or the retailer’s digital locker |
| Refurbished PC | Product key | Provided by the refurbisher |
| Volume Licensing, MSDN | Product key | Your program’s web portal |
Microsoft keeps a record of product keys only if you bought them from its online store, and those purchases appear in your Microsoft account order history. If the key came from somewhere else, the seller’s documents are your proof, so keep the email, receipt, and invoice.
Result: The source of your key matches one of the official options, and you’ve kept your proof of purchase.
What Microsoft considers a genuine key
According to Microsoft, genuine Windows is published by Microsoft, properly licensed, and supported by Microsoft or a trusted partner. You get a key for such a copy in one of the ways listed in the table above. Microsoft says the safest option is to buy Windows from Microsoft or to buy a PC with Windows preinstalled from Microsoft or a store you know and trust.
Where Microsoft recommends buying Windows:
- Microsoft Store: in the app (Settings → System → Activation → Open Store) or on Microsoft’s website. The store isn’t available in every country.
- Authorized retailers: a boxed or digital copy with a product key.
- A new PC with Windows preinstalled. Microsoft calls this the best and most cost-effective way to get genuine, properly licensed software.
Microsoft doesn’t distribute product keys on their own. The exception is Product Key Cards (PKCs), which come with a Certificate of Authenticity (COA).
New PCs with Windows 11 Pro should carry a Genuine Microsoft Label (GML), usually on the back or bottom of the case. Its color shifts as you tilt it, and the label is ruined if someone tries to peel it off. If the key is stored in firmware, there may be no label with the key: such a copy of Windows activates automatically the first time the PC connects to a network.
Signs of a gray-market or counterfeit key
On its How to Tell website, Microsoft lists warning signs to watch for when you buy Windows or a PC that runs it:
- The key is sold on its own on an auction site, in an online ad, or on another page selling keys. For Microsoft, that’s a sign the key is likely stolen or counterfeit.
- The price looks too good to be true. But counterfeiters often price their copies just below the normal retail price, so a normal price isn’t a guarantee either.
- It’s a volume license key. These keys are licensed to a specific business for its employees, and Microsoft may block a key that was stolen and resold. Windows volume licenses are also upgrade-only: the PC must already have a full licensed operating system.
- COA labels without a PC, sold as “excess inventory” or “unused labels.” Certificates of Authenticity aren’t sold separately from a PC or software, and such labels are often counterfeit.
- A fully exposed key on a COA. Since July 2016, part of the 25-character key has been hidden under a silver scratch-off layer. If the whole key is already visible when you buy it, the label may have been tampered with and the key used.
- A recovery disc without the PC. These discs aren’t licensed for separate sale, and Windows installed from one may not activate on another PC.
- A seller with no contact details, or payment in cash or by instant money transfer. Microsoft recommends paying with a secure method and keeping your order page, emails, receipts, and invoices.
- A used PC. The seller may have used the key on more PCs than allowed. Ask for the original Windows disc and the product key or Certificate of Authenticity.
Microsoft also describes the risks. A stolen or counterfeit key may not activate Windows, may already be in use on another PC, or may be blocked later when it’s reported stolen. A non-genuine copy fails online validation, and Windows shows notifications that it might not be genuine. Such a system still gets critical security updates, but many other updates and features are available only for genuine Windows.
If you were sold a counterfeit, Microsoft invites you to report it through the form on its How to Tell site, and reports are treated as confidential. Your saved proof of purchase will help both with the report and with returning the software to the seller.
If Windows won’t activate
Start with the built-in Activation troubleshooter. It needs an internet connection and administrator rights, and the option to run it appears only while Windows isn’t activated.
- Open Settings → System → Activation (on Windows 10, Settings → Update & Security → Activation).
- Select Troubleshoot and wait for the check to finish.
- Follow the prompts: the troubleshooter may find a digital license and activate Windows or tell you which edition your license needs.
If the error persists, look up its code in the table. It’s based on Microsoft’s help page on activation errors.
| Error code | What it means | What to do |
|---|---|---|
| 0xC004F211, 0xC004F213 | Hardware changed, no key found | Reactivate (see the section below) |
| 0xC004F212, 0xC004F210 | Key or license for another edition | Install the edition on your license |
| 0x803F7001, 0x800704CF | No valid license found | Enter a key or buy a license |
| 0xC004C003 | Invalid: key entered on several PCs | Contact the seller or PC maker |
| 0xC004C008, 0xC004C770, 0x803FA071 | Key already used on another PC | Buy a license for this PC |
| 0xC004C060, 0xC004C001, 0xC004F050 | This key can’t activate Windows | Enter a different key |
| 0xC004F074, 0x8007232B | Organization’s key, no access to its network | Contact your organization’s admin |
| 0x80072F8F | Wrong time or no server connection | Check the date, time, and internet |
| 0xC004FC03 | No internet, or a firewall is blocking it | Connect or activate by phone |
To activate by phone, type SLUI 04 in the search box on the taskbar, select SLUI 04 in the results, and follow the on-screen instructions. This option isn’t available for Windows 11 Pro for Workstations or Pro Education: they can only be activated online.
How to transfer your license after a hardware change
A digital license is tied to your PC’s hardware. After a significant change, such as a new motherboard, Windows won’t find a matching license and has to be activated again. Microsoft provides a separate path for transferring the license, but only if it was linked to your Microsoft account in advance.
Before the change
- Make sure Windows is activated: Settings → System → Activation.
- Check your account: under Accounts → Your info, you should see Administrator under your name and an email address above it. If there’s no email address, you’re signed in with a local account.
- On the Activation page, select Add an account, enter your Microsoft account email and password, and select Sign in. The message changes to “Windows is activated with a digital license linked to your Microsoft account.”
- Write down your Windows edition: it has to stay the same after the change. If you activated with a product key, keep the key.
After the change
- Connect the PC to the internet and sign in as an administrator.
- Open Settings → System → Activation → Troubleshoot. The troubleshooter reports that Windows couldn’t be activated on this device.
- Select I changed hardware on this device recently, then select Next.
- Sign in to your linked Microsoft account: the troubleshooter works only with it.
- In the list of devices, check This is the device I’m using right now and select Activate.
If you didn’t link the license but activated Windows with a product key, enter the same key: Activation → Change product key → Change. If Windows came preinstalled and you replaced the motherboard yourself, Microsoft warns you may need a new license. If the PC manufacturer replaced it, Windows should reactivate automatically.
You can’t always move a license to another PC. Under the Windows 11 license terms, preinstalled Windows can be transferred to another person only together with the device. A stand-alone copy can be moved to another PC you own, but you have to remove it from the old one.
Troubleshooting
- There’s no Troubleshoot option: it appears only when Windows isn’t activated.
- The troubleshooter doesn’t list your PC: sign in with the same Microsoft account your license is linked to.
- Windows says the key doesn’t match your country or region: you can’t activate this device with that key, and Windows suggests buying genuine Windows in the Store.
- A home PC shows “Your Windows license will expire soon”: that’s how Windows warns about a volume (KMS) license. Microsoft says this notification appears only on corporate-owned or managed devices; if the PC is personal, you need a retail key from the Microsoft Store.
- Messages about non-genuine Windows appeared after a repair: the technician may have activated Windows with a different key. Enter your original product key.
- The slmgr command won’t run: use Get-OSLicenseInfo in PowerShell, since Microsoft plans to turn VBScript off by default.
- Your error code isn’t in the table: look it up in Microsoft’s help on activation errors or contact Microsoft support.
Sources and methodology
Analysis of public sourcesChecked 25 September 2026
- Microsoft — Activate Windows support.microsoft.com
- Microsoft — About Genuine Windows support.microsoft.com
- Microsoft — Get help with Windows activation errors support.microsoft.com
- Microsoft — Reactivating Windows after a hardware change support.microsoft.com
- Microsoft How to Tell — tips for safer shopping microsoft.com
FAQ
Can I check a Windows key online before activating it?
Microsoft’s help pages don’t offer such a service: the key is verified during activation. Before you buy, judge by the source (the Microsoft Store, an authorized retailer, or a PC with Windows preinstalled) and keep your proof of purchase.
Is it risky to buy a cheap Windows key?
Microsoft warns that keys sold on their own on auction sites, in online ads, and on other pages are likely stolen or counterfeit. Such a key may not activate, may already be in use on another PC, or may be blocked later.
Do I need to enter a key when reinstalling Windows?
Not if your PC has a digital license: install the same edition, select I don’t have a product key when asked for one, and Windows activates online after setup. If you activated with a product key, enter it again. If the installation fails, see our guide to Windows installation errors and fixes.
Where do I find my Windows product key?
It depends on how you bought Windows: in the purchase email, on a label or card inside the box, or on the Certificate of Authenticity (COA) on the case. New PCs often have the key stored in firmware, and a free upgrade or a purchase in the Microsoft Store app gives you a digital license instead of a key.
Can I move Windows to another PC?
A stand-alone copy, yes: to another PC you own, after you remove it from the old one. Under the license terms, preinstalled Windows is transferred only together with the PC. To see your license type, run slmgr /dli: RETAIL means retail, and OEM means it came from the PC manufacturer.
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