It's easy to lose your Windows product key. You might have thrown it away with the packaging that came with your laptop or PC. In many cases there's a sticker somewhere on the machine itself which bears the code, but it may have faded, rubbed off or been damaged over the years.

Luckily, there are apps which will search the Windows Registry and dig out the product key for you. It's encrypted, so don't bother attempting a manual search yourself. 

Instead, download ProduKey or Magical Jelly Bean KeyFinder. Both are free utilities that should be able to find the activation key for Windows XP, Vista, 7, 8 and - in some cases 10.

How to find your Windows product key

With Magical Jelly Bean, you can even use it to scan a Windows installation on another hard drive to extract the key if Windows won't boot. However, you'll need to run it from another working computer with the same version of Windows (XP or Vista). A more powerful alternative if the free tools don't work is Recover Keys.

How do I find my Windows 10 product key?

How to find Windows 10 product key

Windows 10 is a special case, because it doesn't necessarily require a product key like older versions. However, if you purchased a boxed copy of Windows 10, it will be on a label in the box. If you bought a digital copy of Windows 10 online from Microsoft or another site, you should have received the product key in an email.

But if you got your copy of Windows 10 from a free upgrade, or it came with a new PC or laptop, there may be no key at all. That's because Microsoft has an alternative method to a product key called 'digital entitlement'. 

If you bought a PC, laptop or tablet running Windows 10 then it should have a sticker or Certificate of Authenticity which contains the product key, or be included somewhere with the packaging or documentation that came with it.

However, this isn't always the case. One reader told us that, according to HP, it does not put product key on laptops or PCs for security reasons. As with the digital entitlement (now called a Digital Licence), the product key is stored "somewhere in the computer" and will activate automatically if needed. This is supposed to work even if the hard drive fails.

Fortunately, as with older versions, you might be able to extract your Windows 10 product key using ProduKey.

How to find Windows 10 product key - ProduKey

Note: The program might be flagged by your anti-virus program, as it is a tool used to extract keys - some anti-viruses deem this as a virus or malware, but trust us - it's safe. 

Write your Product Key on a piece of paper and store it safely. If you ever need to re-install Windows 10 on another machine or decide to wipe your hard drive, you can now install Windows 10 directly from a Win10 ISO.

Do I need a product key to reinstall Windows 10?

Since Microsoft has your computer’s ‘digital signature’ from the initial upgrade it recognises the combination of components when you do a clean install and automatically activates Windows. This means you can safely skip the screen which asks for a product key at the start of the installation process.

It’s just frustrating that there’s no message to tell you this: the screen is primarily for those installing a version of Windows 10 they’ve purchased and which therefore still requires a key.

So, even if you skip that screen on installation, Windows 10 should activate as long as you haven’t made any major changes to your PC. Upgrading from a hard disk to an SSD won’t affect anything, nor will changing your graphics card. However, upgrading your motherboard and processor will probably count as ‘significant’ and you’ll have to ring Microsoft’s support line if you find that Windows is no longer activated, or you’re reinstalling it.

How do I check if Windows 10 is activated?

Right-click on the Start button and choose System from the menu that appears. Now click on Update & Security, then on Activation in the left-hand menu:

How to check if Windows 10 is activated

At the top you should see the version of Windows 10 and "Activation: Windows is activated". If you see "Activation: Windows is activated with a digital licence” then you won't have a product key as you upgraded from Windows 7 or 8. 

How to check if Windows 10 is activated

Similarly, if you click on Settings on the Start Menu, then Update and Security you will see the section called Activation. If you're running a version prior to the Creators Update, it will look like this:

How to find Windows 10 product key - Activation

What do I do if Windows was activated with a digital licence?

If you can't extract the product key because Windows 10 is using a digital licence, you need to link that licence with your Microsoft account.

Then, even if you upgrade your CPU and motherboard, Windows will still re-activate when you first boot up the upgraded hardware and Windows connects to the internet. (This applies to the Anniversary Update version of Windows 10 and later.)

Here's how to do it:

  • Open the Settings app
  • Click on Accounts
  • Click on Your info
  • Click 'Sign in with a Microsoft account instead' link  (this won't be shown if your PC is connected to a work domain)
  • Sign in with your details
  • Enter your current Windows password
  • Either create a PIN or click 'Skip this step'

Now, to check that the digital licence is properly associated with your Microsoft account, do the following

  • Open the Settings app
  • Click on Update & security
  • Click on Activation
  • Make sure it now reads "Windows is activated with a digital licence linked to your Microsoft account"

That's it: you can now upgrade your hardware and shouldn't have any problems with your Windows 10 licence.

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