Activating Windows 10: How it works under Microsoft's new rules

Microsoft is revamping how it checks if Windows is genuine. Here's how these changes could make your life easier when setting up Windows 10.

The process of upgrading to Microsoft's Windows 10 OS has proved anything but straightforward for some users.

To address these stumbling blocks, Microsoft has simplified the way that Windows 10 is activated - the process of verifying that a copy of Windows is genuine.

These changes should make life easier for users of Windows 7, 8 and 8.1 when they upgrade to or reinstall Windows 10.

In tests of the latest preview build of Windows 10, product keys from Windows 7, 8 and 8.1 were successfully used to activate clean installs of Windows 10 - on a machine that previously had Windows installed and on PCs where Windows had never been installed.

This is significant because earlier builds of Windows 10 would not accept these keys and were activated using an automated system. The system required the user to first upgrade a Windows 7 or 8.1 machine to Windows 10. Once upgraded that PC would be logged in a Microsoft database of computers licensed to run Windows 10. If Windows 10 was then reinstalled on the same machine - provided the PC's hardware hadn't significantly changed - it would be matched against this database and the OS would be automatically activated.

Unfortunately in some instances the system failed to automatically activate Windows 10 and users had to reinstall the old copy of Windows and upgrade to Windows 10 again to get it to activate.

From the latest build of Windows 10 onwards users should be able to bypass a lot of these issues. The changes to activation allow the user to simply enter a Windows 7, 8 or 8.1 key to activate a clean install of Windows in many instances.

Microsoft has confirmed that if you install Windows 10 on a PC that previously ran a genuine copy of Windows 7, 8 or 8.1 that you will be able to use the product key from that earlier operating system to activate Windows 10.

What is less clear is what restrictions there will be on using a product key from an older version of Windows to activate Windows 10 on a different machine, which has never run Windows before.

In his blog post, Microsoft VP Gabe Aul, says that "if you do a clean install of Windows 10 by booting off the media, you can also enter the product key from prior Windows versions on qualifying devices during setup."

What's unclear is what he means by "qualifying devices". I've asked Microsoft to clarify exactly when product keys can be used but have received no response.

As mentioned, one set of tests has found that Windows 8.1 product keys can activate Windows 10 on a brand new machine that has never had Windows installed on it.

However, this is anecdotal evidence from a single user and there is no guarantee this approach will work for others.

This new way of activating Windows was made available in the latest build released to those testing the OS under the Windows 10 Insider Program. The changes, rolled out under Windows Insider Preview Build 10565, are expected to be pushed to all Windows 10 users around November 25th.

Older Windows product keys can only be used to activate an equivalent edition of Windows 10, for example you can't activate Windows 10 Pro on a device that ran Windows 7 Home edition using the Windows 7 Home product key.

What to do

You can enter the product key at a couple of points during the install and setup of Windows 10 but if you miss this you can still add it from the desktop. Here's how to do it.

1. Click on the Start Button

2. Click on Settings

3. Click on Update & security

4. Click on Activation

5. Select Change Product Key

6. Enter the product key from your old copy of Windows (7, 8 or 8.1)

That's it.

As soon as we get more information on exactly when product keys will work when activating Windows 10 we'll update the story.

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