Performing a clean install of Windows 10

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This post details how to do first an upgrade, and then clean install of Windows 10 using the free upgrade, making sure that your PC is activated at the end.

First, make sure that you have backed up your system.

Step 1: Get Windows 10 install files

Option 1: Get the ISOs from Microsoft

The first thing that you need to do is get hold of the ISOs. I would recommend doing it this way rather than using the Get Windows 10 app notification.

  • Go to

  • Download the 32-bit or 64-bit version of the tool that matches your current version of Windows, it doesn’t matter if you are going to install a different version later.

Option 2: Download from MSDN Subscribers

You can also use the MSDN ISOs to do this, I have tested and they work fine.

Login and download from

Note that you will need to use the Multiple Version ISO to do an upgrade, not Enterprise. This version includes both Home and Pro.

I recommend using Rufus to create a bootable USB key from this ISO.

Step 2: Upgrade Windows

It is important to do an in place upgrade first, in order to retain your Windows activation.

Note: You must have a machine currently running a valid copy of Windows 7 or Windows 8.1 for this to work. Note down if you have the Home or Pro version so you know which version you will upgrade to:

Windows 8/8.1 and Windows 7 Home Basic and Home Premium devices upgrade to Windows 10 Home

Windows 8/8.1 Pro and Windows 7 Professional and Ultimate devices upgrade to Windows 10 Pro

Start with Win7 or 8.1 that’s properly activated.

Install Win10 as an upgrade – if you have the Get Windows 10 app, I would recommend using that at this stage, as in my experience the wizard is generally less problematic, this will download Windows 10 again however. You can also run setup.exe from your install media. You could also use the Get Windows 10 app to do this, but using your media avoids downloading it twice. Do not boot from the Win10 install media at this stage, but run setup.exe from your existing Windows installation.

Once Windows 10 is installed, make sure you are connected to the internet.

Right click on the Start button, click System, and make sure that it says Windows 10 is activated. If not, click on the link to activate, making sure that you are connected to the internet.

Step 3: Perform a Clean Install

Once you have Windows 10 upgraded and activated, you can then optionally do a clean install, which will retain your activation status.

Reboot from your bootable USB media and follow the normal steps to install, acknowledge the warning that any previous Windows installation will be lost.

If you used the MSDN media, it will prompt you to choose either Home or Pro – make sure that this is the same edition as you had before (which will be the same as the version of Windows 7 i.e. Home Premium – Home etc).

Choose custom install when prompted, delete all the partitions, and install away.

When it first boots, you will be prompted to enter a product key, click on ‘do this later’.

Once you are logged in, check again in System and it should be activated.

This works because the upgrade is what registers the machine ID with the Microsoft . Once that’s done, any time that machine does an installation, it checks with Microsoft and verifies activation on the machine ID. If the ID is in the database, it activates.

Also see the Microsoft FAQ for more information.

Once your device upgrades to Windows 10 using the free upgrade offer and activates online automatically, an entitlement is registered to your PC’s hardware for your edition of Windows 10.  (If you go to Settings  >> Update & Security >> Activation says “Windows is activated”.)  Now you will be able to clean install (i.e. boot from media and install Windows 10) the same edition of Windows 10 seamlessly without having to enter a product key.

 Make sure your PC is activated by going to the Settings >> Update & Security >> Activation.
If the activation has not completed, you can click the Activate Now button to complete the activation process. 

Create your installation media for the appropriate edition of Windows 10 by clicking here.

Skip entering the product key during Windows 10 Setup. Windows 10 will activate online automatically on such devices. The skip option is only available when booting from media and launching Windows 10 setup

 The automatic online activation will occur seamlessly after clean installing Windows 10 if the device had previously upgraded and activated online, with the same edition of Windows 10.

Posted in Windows 10

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1 Comment

  1. kaisersolo

    Hello BOB,
    I Have A Flex 10 fully upgraded to Windows 10 Home.
    I’m having issue’s with performing a clean install via USB with issues relating to drivers.
    I’ll try this method and get back to you.
    Do you know of any other way to get win 10 on my SSD for the Flex 10
    I have the n3510 cpu & 500GB Hard and the SSD crucial BX100 250GB.

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